diff --git a/build/mach_initialize.py b/build/mach_initialize.py
index d05c2c170bfd..1624a0c0179f 100644
--- a/build/mach_initialize.py
+++ b/build/mach_initialize.py
@@ -14,7 +14,6 @@ if sys.version_info[0] < 3:
     class MetaPathFinder(object):
         pass
 
-
 else:
     from importlib.abc import MetaPathFinder
 
diff --git a/build/moz.configure/memory.configure b/build/moz.configure/memory.configure
index 3a321bfb9560..aa81199ab703 100644
--- a/build/moz.configure/memory.configure
+++ b/build/moz.configure/memory.configure
@@ -58,6 +58,7 @@ set_config("MOZ_REPLACE_MALLOC_STATIC", replace_malloc_static)
 # PHC (Probabilistic Heap Checker)
 # ==============================================================
 
+
 # In general, it only makes sense for PHC to run on the platforms that have a
 # crash reporter.
 @depends(
diff --git a/build/moz.configure/nspr.configure b/build/moz.configure/nspr.configure
index 5c7358ca507c..182a508b735f 100644
--- a/build/moz.configure/nspr.configure
+++ b/build/moz.configure/nspr.configure
@@ -83,6 +83,7 @@ def pkgconf_requires_private(system_nspr, nspr_minver):
 
 set_config("PKGCONF_REQUIRES_PRIVATE", pkgconf_requires_private)
 
+
 # pkg_check_modules takes care of NSPR_CFLAGS and NSPR_LIBS when using --with-system-nspr.
 @depends(build_environment, c_compiler, fold_libs, when=build_nspr)
 def nspr_config(build_env, c_compiler, fold_libs):
diff --git a/build/moz.configure/toolchain.configure b/build/moz.configure/toolchain.configure
index 680f8824def9..39b3bd7fa9a7 100644
--- a/build/moz.configure/toolchain.configure
+++ b/build/moz.configure/toolchain.configure
@@ -1033,6 +1033,7 @@ def sysroot(host_or_target, target_sysroot=None):
         opt = "--with-host-sysroot"
         env = "HOST_SYSROOT"
         when = depends(host)(lambda h: h.kernel == "Linux")
+
         # Only bootstrap a host sysroot when using a bootstrapped target sysroot
         # or when the target doesn't use a bootstrapped sysroot in the first place.
         @depends(when, bootstrap_target_when, target_sysroot.bootstrapped)
@@ -1731,7 +1732,6 @@ def select_linker_tmpl(host_or_target):
     @imports("os")
     @imports("shutil")
     def select_linker(linker, c_compiler, developer_options, toolchain_flags, target):
-
         if linker:
             linker = linker[0]
         else:
@@ -2500,6 +2500,7 @@ def cet_ldflags(c_compiler, target):
 
 set_config("MOZ_CETCOMPAT_LDFLAGS", cet_ldflags)
 
+
 # Frame pointers
 # ==============================================================
 @depends(c_compiler)
@@ -2785,6 +2786,7 @@ add_old_configure_assignment(
     "ENABLE_MOZSEARCH_PLUGIN", depends_if("--enable-mozsearch-plugin")(lambda _: True)
 )
 
+
 # Libstdc++ compatibility hacks
 # ==============================================================
 #
@@ -2966,6 +2968,7 @@ add_old_configure_assignment("LIBFUZZER_FLAGS", libfuzzer_flags.use_flags)
 # Shared library building
 # ==============================================================
 
+
 # XXX: The use of makefile constructs in these variables is awful.
 @depends(target, c_compiler)
 def make_shared_library(target, compiler):
diff --git a/build/moz.configure/update-programs.configure b/build/moz.configure/update-programs.configure
index eb6818ad5670..3be098308d61 100644
--- a/build/moz.configure/update-programs.configure
+++ b/build/moz.configure/update-programs.configure
@@ -4,6 +4,7 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
+
 # Updater
 # ==============================================================
 @depends(build_project)
diff --git a/build/unix/rewrite_sanitizer_dylib.py b/build/unix/rewrite_sanitizer_dylib.py
index 2fa8a92b27f2..59198b13c8c8 100644
--- a/build/unix/rewrite_sanitizer_dylib.py
+++ b/build/unix/rewrite_sanitizer_dylib.py
@@ -60,7 +60,6 @@ def scan_directory(path):
         sys.exit(1)
 
     for file in path.rglob("*"):
-
         if not file.is_file():
             continue
 
diff --git a/config/check_vanilla_allocations.py b/config/check_vanilla_allocations.py
index 10bacd4fd3c1..32e313d38604 100644
--- a/config/check_vanilla_allocations.py
+++ b/config/check_vanilla_allocations.py
@@ -208,7 +208,7 @@ def main():
         if f in ignored_files and (f, 2) in functions:
             fail(f"There should be only one {f} file")
 
-    for (filename, n) in sorted(functions):
+    for filename, n in sorted(functions):
         for fn in functions[(filename, n)]:
             # An allocation is present in a non-special file.  Fail!
             fail("'" + fn + "' present in " + filename)
diff --git a/config/mozunit/mozunit/mozunit.py b/config/mozunit/mozunit/mozunit.py
index b295ad881f6a..28009425b636 100644
--- a/config/mozunit/mozunit/mozunit.py
+++ b/config/mozunit/mozunit/mozunit.py
@@ -219,7 +219,7 @@ class _MockOpen(_MockBaseOpen):
             content = six.ensure_binary(content or b"")
             return MockedBytesFile(self, name, content)
         else:
-            content = six.ensure_text(content or u"")
+            content = six.ensure_text(content or "")
             return MockedStringFile(self, name, content)
 
 
diff --git a/config/tests/unit-nsinstall.py b/config/tests/unit-nsinstall.py
index bfdf259e868c..7584b3827848 100644
--- a/config/tests/unit-nsinstall.py
+++ b/config/tests/unit-nsinstall.py
@@ -146,9 +146,9 @@ class TestNsinstall(unittest.TestCase):
     @unittest.skipIf(not RUN_NON_ASCII_TESTS, "Skipping non ascii tests")
     def test_nsinstall_non_ascii(self):
         "Test that nsinstall handles non-ASCII files"
-        filename = u"\u2325\u3452\u2415\u5081"
+        filename = "\u2325\u3452\u2415\u5081"
         testfile = self.touch(filename)
-        testdir = self.mkdirs(u"\u4241\u1D04\u1414")
+        testdir = self.mkdirs("\u4241\u1D04\u1414")
         self.assertEqual(
             nsinstall([testfile.encode("utf-8"), testdir.encode("utf-8")]), 0
         )
@@ -162,9 +162,9 @@ class TestNsinstall(unittest.TestCase):
     )
     def test_nsinstall_non_ascii_subprocess(self):
         "Test that nsinstall as a subprocess handles non-ASCII files"
-        filename = u"\u2325\u3452\u2415\u5081"
+        filename = "\u2325\u3452\u2415\u5081"
         testfile = self.touch(filename)
-        testdir = self.mkdirs(u"\u4241\u1D04\u1414")
+        testdir = self.mkdirs("\u4241\u1D04\u1414")
         # We don't use subprocess because it can't handle Unicode on
         # Windows <http://bugs.python.org/issue1759845>. mozprocess calls
         # CreateProcessW directly so it's perfect.
diff --git a/devtools/rename.py b/devtools/rename.py
index 04d613742ecd..01383867e773 100644
--- a/devtools/rename.py
+++ b/devtools/rename.py
@@ -4,6 +4,7 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
+
 # Put the content of `filenames[0]` file into `output` file pointer
 def main(output, *filenames):
     with open(filenames[0], "r", encoding="utf-8") as f:
diff --git a/dom/bindings/Codegen.py b/dom/bindings/Codegen.py
index e80e9f728912..5273a76aef0f 100644
--- a/dom/bindings/Codegen.py
+++ b/dom/bindings/Codegen.py
@@ -381,7 +381,7 @@ def fill(template, **args):
 
     t, argModList = compile_fill_template(template)
     # Now apply argModList to args
-    for (name, modified_name, depth) in argModList:
+    for name, modified_name, depth in argModList:
         if not (args[name] == "" or args[name].endswith("\n")):
             raise ValueError(
                 "Argument %s with value %r is missing a newline" % (name, args[name])
@@ -4372,7 +4372,7 @@ def InitUnforgeablePropertiesOnHolder(
         (defineUnforgeableAttrs, properties.unforgeableAttrs),
         (defineUnforgeableMethods, properties.unforgeableMethods),
     ]
-    for (template, array) in unforgeableMembers:
+    for template, array in unforgeableMembers:
         if array.hasNonChromeOnly():
             unforgeables.append(CGGeneric(template % array.variableName(False)))
         if array.hasChromeOnly():
@@ -13021,7 +13021,6 @@ class CGUnionStruct(CGThing):
         return self.type.getDeps()
 
     def getStruct(self):
-
         members = [
             ClassMember("mType", "TypeOrUninit", body="eUninitialized"),
             ClassMember("mValue", "Value"),
@@ -17065,7 +17064,6 @@ class CGDescriptor(CGThing):
 
 class CGNamespacedEnum(CGThing):
     def __init__(self, namespace, enumName, names, values, comment=""):
-
         if not values:
             values = []
 
@@ -23425,7 +23423,6 @@ class GlobalGenRoots:
 
     @staticmethod
     def PrototypeList(config):
-
         # Prototype ID enum.
         descriptorsWithPrototype = config.getDescriptors(
             hasInterfacePrototypeObject=True
@@ -23613,7 +23610,6 @@ class GlobalGenRoots:
 
     @staticmethod
     def RegisterBindings(config):
-
         curr = CGNamespace.build(
             ["mozilla", "dom"], CGGlobalNames(config.windowGlobalNames)
         )
@@ -23641,7 +23637,6 @@ class GlobalGenRoots:
 
     @staticmethod
     def RegisterWorkerBindings(config):
-
         curr = CGRegisterWorkerBindings(config)
 
         # Wrap all of that in our namespaces.
@@ -23668,7 +23663,6 @@ class GlobalGenRoots:
 
     @staticmethod
     def RegisterWorkerDebuggerBindings(config):
-
         curr = CGRegisterWorkerDebuggerBindings(config)
 
         # Wrap all of that in our namespaces.
@@ -23695,7 +23689,6 @@ class GlobalGenRoots:
 
     @staticmethod
     def RegisterWorkletBindings(config):
-
         curr = CGRegisterWorkletBindings(config)
 
         # Wrap all of that in our namespaces.
@@ -23722,7 +23715,6 @@ class GlobalGenRoots:
 
     @staticmethod
     def RegisterShadowRealmBindings(config):
-
         curr = CGRegisterShadowRealmBindings(config)
 
         # Wrap all of that in our namespaces.
diff --git a/dom/bindings/Configuration.py b/dom/bindings/Configuration.py
index d7b14264d8f6..9ac55a72c4bd 100644
--- a/dom/bindings/Configuration.py
+++ b/dom/bindings/Configuration.py
@@ -248,7 +248,7 @@ class Configuration(DescriptorProvider):
                 for m in t.flatMemberTypes:
                     addUnions(m)
 
-        for (t, _) in getAllTypes(self.descriptors, self.dictionaries, self.callbacks):
+        for t, _ in getAllTypes(self.descriptors, self.dictionaries, self.callbacks):
             addUnions(t)
 
         for d in getDictionariesConvertedToJS(
@@ -440,7 +440,7 @@ class Configuration(DescriptorProvider):
                                 name,
                             )
                         )
-                    for (k, v) in firstExtAttrs.items():
+                    for k, v in firstExtAttrs.items():
                         if extAttrs[k] != v:
                             raise TypeError(
                                 "%s on %s and %s on %s have different values for extended attribute %s, but they're using the same template %s."
diff --git a/dom/bindings/parser/WebIDL.py b/dom/bindings/parser/WebIDL.py
index b3976cafa067..8cad33318dcb 100644
--- a/dom/bindings/parser/WebIDL.py
+++ b/dom/bindings/parser/WebIDL.py
@@ -947,7 +947,6 @@ class IDLInterfaceMixin(IDLInterfaceOrInterfaceMixinOrNamespace):
 
     def validate(self):
         for member in self.members:
-
             if member.isAttr():
                 if member.inherit:
                     raise WebIDLError(
@@ -3165,7 +3164,7 @@ class IDLUnionType(IDLType):
                 return "MaybeShared" + type.name
             return type.name
 
-        for (i, type) in enumerate(self.memberTypes):
+        for i, type in enumerate(self.memberTypes):
             if not type.isComplete():
                 self.memberTypes[i] = type.complete(scope)
 
@@ -3206,7 +3205,7 @@ class IDLUnionType(IDLType):
                 continue
             i += 1
 
-        for (i, t) in enumerate(self.flatMemberTypes[:-1]):
+        for i, t in enumerate(self.flatMemberTypes[:-1]):
             for u in self.flatMemberTypes[i + 1 :]:
                 if not t.isDistinguishableFrom(u):
                     raise WebIDLError(
@@ -3619,7 +3618,6 @@ class IDLPromiseType(IDLParametrizedType):
 
 
 class IDLBuiltinType(IDLType):
-
     Types = enum(
         # The integer types
         "byte",
@@ -4287,7 +4285,7 @@ class IDLValue(IDLObject):
                 )
         elif self.type.isInteger() and type.isFloat():
             # Convert an integer literal into float
-            if -(2 ** 24) <= self.value <= 2 ** 24:
+            if -(2**24) <= self.value <= 2**24:
                 return IDLValue(self.location, type, float(self.value))
             else:
                 raise WebIDLError(
@@ -4468,7 +4466,6 @@ class IDLUndefinedValue(IDLObject):
 
 
 class IDLInterfaceMember(IDLObjectWithIdentifier, IDLExposureMixins):
-
     Tags = enum(
         "Const", "Attr", "Method", "MaplikeOrSetlike", "AsyncIterable", "Iterable"
     )
@@ -5791,7 +5788,7 @@ class IDLAttribute(IDLInterfaceMember):
             "CrossOriginWritable",
             "SetterThrows",
         ]
-        for (key, value) in self._extendedAttrDict.items():
+        for key, value in self._extendedAttrDict.items():
             if key in allowedExtAttrs:
                 if value is not True:
                     raise WebIDLError(
@@ -5968,7 +5965,7 @@ class IDLCallback(IDLObjectWithScope):
 
         IDLObjectWithScope.__init__(self, location, parentScope, identifier)
 
-        for (returnType, arguments) in self.signatures():
+        for returnType, arguments in self.signatures():
             for argument in arguments:
                 argument.resolve(self)
 
@@ -6109,7 +6106,6 @@ class IDLMethodOverload:
 
 
 class IDLMethod(IDLInterfaceMember, IDLScope):
-
     Special = enum(
         "Getter", "Setter", "Deleter", "LegacyCaller", base=IDLInterfaceMember.Special
     )
@@ -6292,7 +6288,7 @@ class IDLMethod(IDLInterfaceMember, IDLScope):
         assert isinstance(parentScope, IDLScope)
         IDLObjectWithIdentifier.resolve(self, parentScope)
         IDLScope.__init__(self, self.location, parentScope, self.identifier)
-        for (returnType, arguments) in self.signatures():
+        for returnType, arguments in self.signatures():
             for argument in arguments:
                 argument.resolve(self)
 
@@ -6435,7 +6431,7 @@ class IDLMethod(IDLInterfaceMember, IDLScope):
             variadicArgument = None
 
             arguments = overload.arguments
-            for (idx, argument) in enumerate(arguments):
+            for idx, argument in enumerate(arguments):
                 assert argument.type.isComplete()
 
                 if (
@@ -6568,8 +6564,8 @@ class IDLMethod(IDLInterfaceMember, IDLScope):
 
     def distinguishingIndexForArgCount(self, argc):
         def isValidDistinguishingIndex(idx, signatures):
-            for (firstSigIndex, (firstRetval, firstArgs)) in enumerate(signatures[:-1]):
-                for (secondRetval, secondArgs) in signatures[firstSigIndex + 1 :]:
+            for firstSigIndex, (firstRetval, firstArgs) in enumerate(signatures[:-1]):
+                for secondRetval, secondArgs in signatures[firstSigIndex + 1 :]:
                     if idx < len(firstArgs):
                         firstType = firstArgs[idx].type
                     else:
diff --git a/dom/bindings/parser/tests/test_attributes_on_types.py b/dom/bindings/parser/tests/test_attributes_on_types.py
index d0a0c7a72ca5..cbd8bfb37ae4 100644
--- a/dom/bindings/parser/tests/test_attributes_on_types.py
+++ b/dom/bindings/parser/tests/test_attributes_on_types.py
@@ -337,7 +337,7 @@ def WebIDLTest(parser, harness):
         ),
     ]
 
-    for (name, template) in TEMPLATES:
+    for name, template in TEMPLATES:
         parser = parser.reset()
         threw = False
         try:
@@ -346,7 +346,7 @@ def WebIDLTest(parser, harness):
         except Exception:
             threw = True
         harness.ok(not threw, "Template for %s parses without attributes" % name)
-        for (attribute, type) in ATTRIBUTES:
+        for attribute, type in ATTRIBUTES:
             parser = parser.reset()
             threw = False
             try:
diff --git a/dom/bindings/parser/tests/test_callback_interface.py b/dom/bindings/parser/tests/test_callback_interface.py
index 1396eb8a2493..cbc87e781180 100644
--- a/dom/bindings/parser/tests/test_callback_interface.py
+++ b/dom/bindings/parser/tests/test_callback_interface.py
@@ -94,7 +94,7 @@ def WebIDLTest(parser, harness):
     """
     )
     results = parser.finish()
-    for (i, iface) in enumerate(results):
+    for i, iface in enumerate(results):
         harness.check(
             iface.isSingleOperationInterface(),
             i < 4,
diff --git a/dom/bindings/parser/tests/test_const.py b/dom/bindings/parser/tests/test_const.py
index ea597d1ed203..22600a9946e6 100644
--- a/dom/bindings/parser/tests/test_const.py
+++ b/dom/bindings/parser/tests/test_const.py
@@ -64,7 +64,7 @@ def WebIDLTest(parser, harness):
         len(iface.members), len(expected), "Expect %s members" % len(expected)
     )
 
-    for (const, (QName, name, type, value)) in zip(iface.members, expected):
+    for const, (QName, name, type, value) in zip(iface.members, expected):
         harness.ok(isinstance(const, WebIDL.IDLConst), "Should be an IDLConst")
         harness.ok(const.isConst(), "Const is a const")
         harness.ok(not const.isAttr(), "Const is not an attr")
diff --git a/dom/bindings/parser/tests/test_constructor.py b/dom/bindings/parser/tests/test_constructor.py
index 1e1382336ce5..84236565f644 100644
--- a/dom/bindings/parser/tests/test_constructor.py
+++ b/dom/bindings/parser/tests/test_constructor.py
@@ -87,7 +87,7 @@ def WebIDLTest(parser, harness):
         )
 
         sigpairs = zip(method.signatures(), signatures)
-        for (gotSignature, expectedSignature) in sigpairs:
+        for gotSignature, expectedSignature in sigpairs:
             (gotRetType, gotArgs) = gotSignature
             (expectedRetType, expectedArgs) = expectedSignature
 
diff --git a/dom/bindings/parser/tests/test_float_types.py b/dom/bindings/parser/tests/test_float_types.py
index 5cb940469953..ca0b606434e7 100644
--- a/dom/bindings/parser/tests/test_float_types.py
+++ b/dom/bindings/parser/tests/test_float_types.py
@@ -55,7 +55,7 @@ def WebIDLTest(parser, harness):
     method = iface.members[6]
     harness.ok(isinstance(method, WebIDL.IDLMethod), "Should be an IDLMethod")
     argtypes = [a.type for a in method.signatures()[0][1]]
-    for (idx, type) in enumerate(argtypes):
+    for idx, type in enumerate(argtypes):
         harness.ok(type.isFloat(), "Type %d should be float" % idx)
         harness.check(
             type.isUnrestricted(),
diff --git a/dom/bindings/parser/tests/test_method.py b/dom/bindings/parser/tests/test_method.py
index e11044b74296..081190f33bc7 100644
--- a/dom/bindings/parser/tests/test_method.py
+++ b/dom/bindings/parser/tests/test_method.py
@@ -90,7 +90,7 @@ def WebIDLTest(parser, harness):
         )
 
         sigpairs = zip(method.signatures(), signatures)
-        for (gotSignature, expectedSignature) in sigpairs:
+        for gotSignature, expectedSignature in sigpairs:
             (gotRetType, gotArgs) = gotSignature
             (expectedRetType, expectedArgs) = expectedSignature
 
diff --git a/dom/bindings/parser/tests/test_observableArray.py b/dom/bindings/parser/tests/test_observableArray.py
index 601f626bcf46..7fe9511e0749 100644
--- a/dom/bindings/parser/tests/test_observableArray.py
+++ b/dom/bindings/parser/tests/test_observableArray.py
@@ -4,7 +4,6 @@
 
 
 def WebIDLTest(parser, harness):
-
     # Test dictionary as inner type
     harness.should_throw(
         parser,
diff --git a/dom/bindings/parser/tests/test_unenumerable_own_properties.py b/dom/bindings/parser/tests/test_unenumerable_own_properties.py
index 37e016769610..e9cf1b4f55c9 100644
--- a/dom/bindings/parser/tests/test_unenumerable_own_properties.py
+++ b/dom/bindings/parser/tests/test_unenumerable_own_properties.py
@@ -1,5 +1,4 @@
 def WebIDLTest(parser, harness):
-
     parser.parse(
         """
         interface Foo {};
diff --git a/dom/bindings/parser/tests/test_union.py b/dom/bindings/parser/tests/test_union.py
index 675e2d026416..1991a1149c08 100644
--- a/dom/bindings/parser/tests/test_union.py
+++ b/dom/bindings/parser/tests/test_union.py
@@ -89,7 +89,7 @@ def WebIDLTest(parser, harness):
         interface PrepareForTest {
         """
     )
-    for (i, type) in enumerate(types):
+    for i, type in enumerate(types):
         interface += string.Template(
             """
           readonly attribute ${type} attr${i};
@@ -155,7 +155,7 @@ def WebIDLTest(parser, harness):
         interface TestUnion {
         """
     )
-    for (i, type) in enumerate(validUnionTypes):
+    for i, type in enumerate(validUnionTypes):
         interface += string.Template(
             """
           undefined method${i}(${type} arg);
diff --git a/dom/cache/test/marionette/test_caches_delete_cleanup_after_shutdown.py b/dom/cache/test/marionette/test_caches_delete_cleanup_after_shutdown.py
index 4427d1c9c7d9..f1b9cee35b05 100644
--- a/dom/cache/test/marionette/test_caches_delete_cleanup_after_shutdown.py
+++ b/dom/cache/test/marionette/test_caches_delete_cleanup_after_shutdown.py
@@ -140,7 +140,6 @@ class CachesDeleteCleanupAtShutdownTestCase(MarionetteTestCase):
         beforeUsage = self.getUsage()
 
         def ensureCleanCallback():
-
             Wait(self.marionette, timeout=60).until(
                 lambda x: (self.getUsage() - beforeUsage)
                 < EXPECTED_CACHEDIR_SIZE_AFTER_CLEANUP,
diff --git a/dom/canvas/test/webgl-conf/generate-wrappers-and-manifest.py b/dom/canvas/test/webgl-conf/generate-wrappers-and-manifest.py
index b8f4264994b6..cfe19bf6eb19 100755
--- a/dom/canvas/test/webgl-conf/generate-wrappers-and-manifest.py
+++ b/dom/canvas/test/webgl-conf/generate-wrappers-and-manifest.py
@@ -510,7 +510,7 @@ def LoadErrata():
 
     ret = {}
 
-    for (sectionName, (sectionLineNum, sectionMap)) in iniMap.items():
+    for sectionName, (sectionLineNum, sectionMap) in iniMap.items():
         curLines = []
 
         if sectionName is None:
@@ -521,7 +521,7 @@ def LoadErrata():
                 sectionLineNum, sectionName
             )
 
-        for (key, (lineNum, val)) in sectionMap.items():
+        for key, (lineNum, val) in sectionMap.items():
             assert key in ACCEPTABLE_ERRATA_KEYS, "Line {}: {}".format(lineNum, key)
 
             curLine = "{} = {}".format(key, val)
diff --git a/dom/media/webrtc/transport/test/moz.build b/dom/media/webrtc/transport/test/moz.build
index 69d3a587a501..a2b0bc2bc21a 100644
--- a/dom/media/webrtc/transport/test/moz.build
+++ b/dom/media/webrtc/transport/test/moz.build
@@ -7,7 +7,6 @@
 include("/ipc/chromium/chromium-config.mozbuild")
 
 if CONFIG["OS_TARGET"] != "WINNT":
-
     if CONFIG["OS_TARGET"] != "Android":
         SOURCES += [
             "ice_unittest.cpp",
diff --git a/dom/websocket/tests/file_websocket_wsh.py b/dom/websocket/tests/file_websocket_wsh.py
index de69f747e888..65cfe39994dc 100644
--- a/dom/websocket/tests/file_websocket_wsh.py
+++ b/dom/websocket/tests/file_websocket_wsh.py
@@ -81,7 +81,7 @@ def web_socket_transfer_data(request):
         msgutil.send_message(request, six.ensure_text(resp))
     elif request.ws_protocol == "test-12":
         msg = msgutil.receive_message(request)
-        if msg == u"a\ufffdb":
+        if msg == "a\ufffdb":
             # converted unpaired surrogate in UTF-16 to UTF-8 OK
             msgutil.send_message(request, "SUCCESS")
         else:
diff --git a/gfx/angle/update-angle.py b/gfx/angle/update-angle.py
index 57714e40d25b..029a81cbdb22 100755
--- a/gfx/angle/update-angle.py
+++ b/gfx/angle/update-angle.py
@@ -485,7 +485,7 @@ def export_target(target_full_name) -> Set[str]:
     append_arr(lines, "LOCAL_INCLUDES", fixup_paths(desc["include_dirs"]))
     append_arr_commented(lines, "CXXFLAGS", cxxflags)
 
-    for (config, v) in sorted_items(sources_by_config):
+    for config, v in sorted_items(sources_by_config):
         indent = 0
         if config:
             lines.append("if {}:".format(config))
@@ -506,7 +506,7 @@ def export_target(target_full_name) -> Set[str]:
     append_arr(lines, "OS_LIBS", os_libs)
     append_arr_commented(lines, "LDFLAGS", ldflags)
 
-    for (k, v) in sorted(extras.items()):
+    for k, v in sorted(extras.items()):
         lines.append("{} = {}".format(k, v))
 
     lib_type = desc["type"]
diff --git a/gfx/thebes/gencjkcisvs.py b/gfx/thebes/gencjkcisvs.py
index 1797f2be6c95..6a28e7d49208 100644
--- a/gfx/thebes/gencjkcisvs.py
+++ b/gfx/thebes/gencjkcisvs.py
@@ -35,7 +35,7 @@ f.close
 
 offsets = []
 length = 10 + 11 * len(vsdict)
-for (k, mappings) in sorted(vsdict.items()):
+for k, mappings in sorted(vsdict.items()):
     offsets.append(length)
     length += 4 + 5 * len(mappings)
 
@@ -69,10 +69,10 @@ for i, k in enumerate(sorted(vsdict.keys())):
         "    U24(0x%04X), U32(0), U32(%d), // varSelectorRecord[%d]\n"
         % (k, offsets[i], i)
     )
-for (k, mappings) in sorted(vsdict.items()):
+for k, mappings in sorted(vsdict.items()):
     f.write("  // 0x%04X\n" % k)
     f.write("  U32(%d), // numUVSMappings\n" % len(mappings))
-    for (unified, compat) in sorted(mappings.items()):
+    for unified, compat in sorted(mappings.items()):
         f.write("    U24(0x%04X), GLYPH(0x%04X),\n" % (unified, compat))
 f.write(
     """};
diff --git a/hal/moz.build b/hal/moz.build
index bc13c596c0d1..f3faf43d395e 100644
--- a/hal/moz.build
+++ b/hal/moz.build
@@ -46,7 +46,6 @@ if CONFIG["MOZ_WIDGET_TOOLKIT"] == "android":
         "android/AndroidHal.cpp",
     ]
 elif CONFIG["OS_TARGET"] == "Linux":
-
     UNIFIED_SOURCES += [
         "fallback/FallbackScreenConfiguration.cpp",
         "fallback/FallbackSensor.cpp",
diff --git a/ipc/ipdl/ipdl.py b/ipc/ipdl/ipdl.py
index 1770416aaac9..230e0a213f72 100644
--- a/ipc/ipdl/ipdl.py
+++ b/ipc/ipdl/ipdl.py
@@ -234,7 +234,7 @@ enum IPCMessages {
 )
 
 for protocol in sorted(allmessages.keys()):
-    for (msg, num) in allmessages[protocol].idnums:
+    for msg, num in allmessages[protocol].idnums:
         if num:
             print("  %s = %s," % (msg, num), file=ipc_msgtype_name)
         elif not msg.endswith("End"):
@@ -256,7 +256,7 @@ const char* StringFromIPCMessageType(uint32_t aMessageType)
 )
 
 for protocol in sorted(allmessages.keys()):
-    for (msg, num) in allmessages[protocol].idnums:
+    for msg, num in allmessages[protocol].idnums:
         if num or msg.endswith("End"):
             continue
         print(
diff --git a/ipc/ipdl/ipdl/lower.py b/ipc/ipdl/ipdl/lower.py
index 38ec6d1abba1..f1d51653f023 100644
--- a/ipc/ipdl/ipdl/lower.py
+++ b/ipc/ipdl/ipdl/lower.py
@@ -64,9 +64,9 @@ class LowerToCxx:
 
 
 def hashfunc(value):
-    h = hash_str(value) % 2 ** 32
+    h = hash_str(value) % 2**32
     if h < 0:
-        h += 2 ** 32
+        h += 2**32
     return h
 
 
@@ -2275,7 +2275,7 @@ class _ParamTraits:
         # After non-pod data, bulk read/write pod data in member order. This has
         # to be done after the result has been constructed, so that we have
         # somewhere to read into.
-        for (size, fields) in itertools.groupby(
+        for size, fields in itertools.groupby(
             sd.fields_member_order(), lambda f: pod_size(f.ipdltype)
         ):
             if size != pod_size_sentinel:
@@ -2517,7 +2517,7 @@ class _ComputeTypeDeps(TypeVisitor):
 
 def _fieldStaticAssertions(sd):
     staticasserts = []
-    for (size, fields) in itertools.groupby(
+    for size, fields in itertools.groupby(
         sd.fields_member_order(), lambda f: pod_size(f.ipdltype)
     ):
         if size == pod_size_sentinel:
diff --git a/ipc/ipdl/ipdl/type.py b/ipc/ipdl/ipdl/type.py
index e063f2b8f940..c050b09345a0 100644
--- a/ipc/ipdl/ipdl/type.py
+++ b/ipc/ipdl/ipdl/type.py
@@ -1721,7 +1721,6 @@ class CheckTypes(TcheckVisitor):
             )
 
         if mtype.compress and (not mtype.isAsync() or mtype.isCtor() or mtype.isDtor()):
-
             if mtype.isCtor() or mtype.isDtor():
                 message_type = "constructor" if mtype.isCtor() else "destructor"
                 error_message = (
diff --git a/ipc/pull-chromium.py b/ipc/pull-chromium.py
index 4f9a7d2f7633..688098b511bc 100644
--- a/ipc/pull-chromium.py
+++ b/ipc/pull-chromium.py
@@ -20,11 +20,11 @@ from subprocess import check_call
 topsrcdir, chromiumtree, rev = sys.argv[1:]
 
 if not os.path.exists(os.path.join(topsrcdir, "client.py")):
-    print >>sys.stderr, "Incorrect topsrcdir"
+    print >> sys.stderr, "Incorrect topsrcdir"
     sys.exit(1)
 
 if not os.path.exists(os.path.join(chromiumtree, "src/DEPS")):
-    print >>sys.stderr, "Incorrect chromium directory, missing DEPS"
+    print >> sys.stderr, "Incorrect chromium directory, missing DEPS"
     sys.exit(1)
 
 check_call(["gclient", "sync", "--force", "--revision=src@%s" % rev], cwd=chromiumtree)
diff --git a/js/ffi.configure b/js/ffi.configure
index ec4e572c7a1b..a8a7ca1c7b9b 100644
--- a/js/ffi.configure
+++ b/js/ffi.configure
@@ -26,6 +26,7 @@ building_ffi = depends(system_ffi)(lambda v: v is None)
 
 set_config("MOZ_SYSTEM_FFI", depends_if(system_ffi)(lambda _: True))
 
+
 # Target selection, based on ffi/configure.ac.
 @depends(target, when=building_ffi)
 def ffi_target(target):
diff --git a/js/moz.configure b/js/moz.configure
index 4adc868069d6..f4a1f0dea5cd 100644
--- a/js/moz.configure
+++ b/js/moz.configure
@@ -173,6 +173,7 @@ def enable_decorators(value):
 set_config("ENABLE_DECORATORS", enable_decorators)
 set_define("ENABLE_DECORATORS", enable_decorators)
 
+
 # JIT support
 # =======================================================
 @depends(target, "--enable-record-tuple")
@@ -506,6 +507,7 @@ set_config("JS_MASM_VERBOSE", depends_if("--enable-masm-verbose")(lambda _: True
 # Architecture feature flags
 # =======================================================
 
+
 # Apple silicon does not seem to have any way to query the OS for the JSCVT
 # flag stored in the ID_AA64ISAR1_EL1 system register. In the mean time, we
 # hard code the value of the JSCVT flag which guards the implementation of
@@ -521,6 +523,7 @@ option(
     help="{Enable|Disable} static use of FJCVTZS instruction on Aarch64 targets.",
 )
 
+
 # The "ARM Architecture Reference Manual" for ARMv8 defines the JSCVT flag as
 # being a 4 bit integer (D12.2.52) and it can be manipulated using >= operator
 # (D12.1.4).
@@ -549,6 +552,7 @@ def has_pthread_jit_write_protect_np(target):
 # JIT code write protection.
 set_define("JS_USE_APPLE_FAST_WX", True, when=has_pthread_jit_write_protect_np)
 
+
 # CTypes
 # =======================================================
 @depends(js_standalone)
diff --git a/js/src/builtin/intl/make_intl_data.py b/js/src/builtin/intl/make_intl_data.py
index ff631ce21975..7042c0a005d0 100755
--- a/js/src/builtin/intl/make_intl_data.py
+++ b/js/src/builtin/intl/make_intl_data.py
@@ -99,7 +99,7 @@ def writeMappingsVar(println, mapping, name, description, source, url):
     println("")
     writeMappingHeader(println, description, source, url)
     println("var {0} = {{".format(name))
-    for (key, value) in sorted(mapping.items(), key=itemgetter(0)):
+    for key, value in sorted(mapping.items(), key=itemgetter(0)):
         println('    "{0}": "{1}",'.format(key, value))
     println("};")
 
@@ -173,7 +173,7 @@ def writeMappingsBinarySearchBody(
     # for the binary search, which only performs a single |memcmp| for multiple
     # of two subtag lengths.
     mappings_keys = mappings.keys() if type(mappings) == dict else mappings
-    for (length, subtags) in groupby(sorted(mappings_keys, key=len), len):
+    for length, subtags in groupby(sorted(mappings_keys, key=len), len):
         # Omit the length check if the current length is the maximum length.
         if length != tag_maxlength:
             println(
@@ -318,7 +318,7 @@ void mozilla::intl::Locale::PerformComplexLanguageMappings() {
 
     # Merge duplicate language entries.
     language_aliases = {}
-    for (deprecated_language, (language, script, region)) in sorted(
+    for deprecated_language, (language, script, region) in sorted(
         complex_language_mappings.items(), key=itemgetter(0)
     ):
         key = (language, script, region)
@@ -328,7 +328,7 @@ void mozilla::intl::Locale::PerformComplexLanguageMappings() {
             language_aliases[key].append(deprecated_language)
 
     first_language = True
-    for (deprecated_language, (language, script, region)) in sorted(
+    for deprecated_language, (language, script, region) in sorted(
         complex_language_mappings.items(), key=itemgetter(0)
     ):
         key = (language, script, region)
@@ -422,7 +422,7 @@ void mozilla::intl::Locale::PerformComplexRegionMappings() {
 
     # Merge duplicate region entries.
     region_aliases = {}
-    for (deprecated_region, (default, non_default_replacements)) in sorted(
+    for deprecated_region, (default, non_default_replacements) in sorted(
         complex_region_mappings.items(), key=itemgetter(0)
     ):
         key = hash_key(default, non_default_replacements)
@@ -432,7 +432,7 @@ void mozilla::intl::Locale::PerformComplexRegionMappings() {
             region_aliases[key].append(deprecated_region)
 
     first_region = True
-    for (deprecated_region, (default, non_default_replacements)) in sorted(
+    for deprecated_region, (default, non_default_replacements) in sorted(
         complex_region_mappings.items(), key=itemgetter(0)
     ):
         key = hash_key(default, non_default_replacements)
@@ -587,7 +587,7 @@ bool mozilla::intl::Locale::PerformVariantMappings() {
         )
     )
 
-    for (deprecated_variant, (type, replacement)) in sorted(
+    for deprecated_variant, (type, replacement) in sorted(
         with_alias, key=itemgetter(0)
     ):
         println(
@@ -730,7 +730,7 @@ bool mozilla::intl::Locale::UpdateLegacyMappings() {
 
     # Group the mappings by language.
     legacy_mappings_by_language = {}
-    for (type, replacement) in legacy_mappings.items():
+    for type, replacement in legacy_mappings.items():
         (language, _, _, _) = type
         legacy_mappings_by_language.setdefault(language, {})[type] = replacement
 
@@ -820,7 +820,7 @@ bool mozilla::intl::Locale::UpdateLegacyMappings() {
     def hash_key(mappings):
         return str(sorted(mappings.items(), key=itemgetter(0)))
 
-    for (lang, mappings) in sorted(
+    for lang, mappings in sorted(
         legacy_mappings_by_language.items(), key=itemgetter(0)
     ):
         key = hash_key(mappings)
@@ -848,10 +848,9 @@ bool mozilla::intl::Locale::UpdateLegacyMappings() {
             return len(k.split("-"))
 
         # Alias rules are applied by largest union size first.
-        for (size, mappings_by_size) in groupby(
+        for size, mappings_by_size in groupby(
             sorted(mappings.items(), key=variant_size, reverse=True), key=variant_size
         ):
-
             # Convert grouper object to dict.
             mappings_by_size = dict(mappings_by_size)
 
@@ -859,7 +858,7 @@ bool mozilla::intl::Locale::UpdateLegacyMappings() {
             chain_if = size == 1
 
             # Alias rules are applied in alphabetical order
-            for (variants, r_language) in sorted(
+            for variants, r_language in sorted(
                 mappings_by_size.items(), key=itemgetter(0)
             ):
                 sorted_variants = sorted(variants.split("-"))
@@ -868,7 +867,7 @@ bool mozilla::intl::Locale::UpdateLegacyMappings() {
                 maybe_else = "else " if chain_if and not is_first else ""
                 is_first = False
 
-                for (i, variant) in enumerate(sorted_variants):
+                for i, variant in enumerate(sorted_variants):
                     println(
                         f"""
     {"  " * i}{maybe_else}if (auto* {variant} = findVariant("{variant}")) {{
@@ -1106,11 +1105,11 @@ def readSupplementalData(core_file):
         # Compute the transitive closure.
         # Any case which currently doesn't occur in the CLDR sources isn't supported
         # and will lead to throwing an error.
-        for (type, replacement) in rules.items():
+        for type, replacement in rules.items():
             (language, script, region, variants) = type
             (r_language, r_script, r_region, r_variants) = replacement
 
-            for (i_type, i_replacement) in rules.items():
+            for i_type, i_replacement in rules.items():
                 (i_language, i_script, i_region, i_variants) = i_type
                 (i_r_language, i_r_script, i_r_region, i_r_variants) = i_replacement
 
@@ -1257,7 +1256,7 @@ def readSupplementalData(core_file):
     variant_mappings = {}
 
     # Preprocess all rules so we can perform a single lookup per subtag at runtime.
-    for (type, replacement) in rules.items():
+    for type, replacement in rules.items():
         (language, script, region, variants) = type
         (r_language, r_script, r_region, r_variants) = replacement
 
@@ -1399,7 +1398,7 @@ def readSupplementalData(core_file):
 
     complex_region_mappings_final = {}
 
-    for (deprecated_region, replacements) in complex_region_mappings.items():
+    for deprecated_region, replacements in complex_region_mappings.items():
         # Find all likely subtag entries which don't already contain a region
         # subtag and whose target region is in the list of replacement regions.
         region_likely_subtags = [
@@ -2507,7 +2506,7 @@ def readICULegacyZones(icuDir):
 
     # A handful of non-IANA zones/links are not in icuzones and must be added
     # manually so that we won't invoke ICU with them.
-    for (zone, target) in otherICULegacyLinks().items():
+    for zone, target in otherICULegacyLinks().items():
         if zone in links:
             if links[zone] != target:
                 raise KeyError(
@@ -2712,7 +2711,7 @@ def processTimeZones(
         println("// Format:")
         println('// "ZoneName" // ICU-Name [time zone file]')
         println("const char* const ianaZonesTreatedAsLinksByICU[] = {")
-        for (zone, icuZone) in incorrectZones:
+        for zone, icuZone in incorrectZones:
             println('    "%s", // %s [%s]' % (zone, icuZone, zone.filename))
         println("};")
         println("")
@@ -2726,7 +2725,7 @@ def processTimeZones(
         println("};")
         println("")
         println("const LinkAndTarget ianaLinksCanonicalizedDifferentlyByICU[] = {")
-        for (zone, target, icuTarget) in incorrectLinks:
+        for zone, target, icuTarget in incorrectLinks:
             println(
                 '    { "%s", "%s" }, // %s [%s]'
                 % (zone, target, icuTarget, zone.filename)
@@ -2796,7 +2795,7 @@ const tzMapper = [
 
         println(description)
         println("const links = {")
-        for (zone, target) in sorted(links, key=itemgetter(0)):
+        for zone, target in sorted(links, key=itemgetter(0)):
             println('    "%s": "%s",' % (zone, target))
         println("};")
 
@@ -3150,10 +3149,10 @@ def writeCurrencyFile(published, currencies, out):
  */"""
         )
         println("var currencyDigits = {")
-        for (currency, entries) in groupby(
+        for currency, entries in groupby(
             sorted(currencies, key=itemgetter(0)), itemgetter(0)
         ):
-            for (_, minorUnits, currencyName, countryName) in entries:
+            for _, minorUnits, currencyName, countryName in entries:
                 println("  // {} ({})".format(currencyName, countryName))
             println("  {}: {},".format(currency, minorUnits))
         println("};")
@@ -3319,7 +3318,7 @@ const char* mozilla::intl::Locale::Replace{0}ExtensionType(
 
     # Merge duplicate keys.
     key_aliases = {}
-    for (key, replacements) in sorted(mapping.items(), key=itemgetter(0)):
+    for key, replacements in sorted(mapping.items(), key=itemgetter(0)):
         hash_key = to_hash_key(replacements)
         if hash_key not in key_aliases:
             key_aliases[hash_key] = []
@@ -3327,7 +3326,7 @@ const char* mozilla::intl::Locale::Replace{0}ExtensionType(
             key_aliases[hash_key].append(key)
 
     first_key = True
-    for (key, replacements) in sorted(mapping.items(), key=itemgetter(0)):
+    for key, replacements in sorted(mapping.items(), key=itemgetter(0)):
         hash_key = to_hash_key(replacements)
         if key in key_aliases[hash_key]:
             continue
@@ -3368,7 +3367,7 @@ const char* mozilla::intl::Locale::Replace{0}ExtensionType(
                 )
             )
         else:
-            for (type, replacement) in replacements:
+            for type, replacement in replacements:
                 println(
                     """
     if (Is{}Type(type, "{}")) {{
diff --git a/js/src/devtools/gc/gc-test.py b/js/src/devtools/gc/gc-test.py
index 9b8fbc25b1e2..80a8d78b7700 100644
--- a/js/src/devtools/gc/gc-test.py
+++ b/js/src/devtools/gc/gc-test.py
@@ -166,7 +166,7 @@ if __name__ == "__main__":
     test_list = find_tests(test_dir)
 
     if not test_list:
-        print >>sys.stderr, "No tests found matching command line arguments."
+        print >> sys.stderr, "No tests found matching command line arguments."
         sys.exit(0)
 
     test_list = [Test.from_file(tst, name, OPTIONS) for tst, name in test_list]
@@ -178,7 +178,7 @@ if __name__ == "__main__":
 
     except OSError:
         if not os.path.exists(JS):
-            print >>sys.stderr, "JS shell argument: file does not exist: '%s'" % JS
+            print >> sys.stderr, "JS shell argument: file does not exist: '%s'" % JS
             sys.exit(1)
         else:
             raise
diff --git a/js/src/devtools/rootAnalysis/analyze.py b/js/src/devtools/rootAnalysis/analyze.py
index ab1d04c2a801..dd37991d4100 100755
--- a/js/src/devtools/rootAnalysis/analyze.py
+++ b/js/src/devtools/rootAnalysis/analyze.py
@@ -212,7 +212,7 @@ JOBS = {
 #  - item is command[j]
 def out_indexes(command):
     i = 0
-    for (j, fragment) in enumerate(command):
+    for j, fragment in enumerate(command):
         if isinstance(fragment, Output):
             yield (i, j, fragment)
             i += 1
@@ -221,7 +221,7 @@ def out_indexes(command):
 def job_command_with_final_output_names(job):
     outfiles = job.get("outputs", [])
     command = list(job["command"])
-    for (i, j, name) in out_indexes(job["command"]):
+    for i, j, name in out_indexes(job["command"]):
         command[j] = outfiles[i]
     return command
 
@@ -256,7 +256,7 @@ def run_job(name, config):
             info["redirect"].close()
 
         # Rename the temporary files to their final names.
-        for (temp, final) in info["rename_map"].items():
+        for temp, final in info["rename_map"].items():
             try:
                 if config["verbose"] > 1:
                     print("Renaming %s -> %s" % (temp, final))
@@ -285,7 +285,7 @@ def spawn_command(cmdspec, job, name, config):
         # from those temp names to their actual final names that will be used
         # if the command succeeds.
         command = list(cmdspec)
-        for (i, j, raw_name) in out_indexes(cmdspec):
+        for i, j, raw_name in out_indexes(cmdspec):
             [name] = fill([raw_name], config)
             command[j] = "{}.tmp{}".format(name, config.get("i", ""))
             rename_map[command[j]] = outfiles[i]
@@ -305,7 +305,7 @@ def spawn_command(cmdspec, job, name, config):
 
 
 # Default to conservatively assuming 4GB/job.
-def max_parallel_jobs(job_size=4 * 2 ** 30):
+def max_parallel_jobs(job_size=4 * 2**30):
     """Return the max number of parallel jobs we can run without overfilling
     memory, assuming heavyweight jobs."""
     from_cores = int(subprocess.check_output(["nproc", "--ignore=1"]).strip())
@@ -434,7 +434,7 @@ for step in steps:
     elif "outputs" in job and "command" in job:
         outfiles = job["outputs"]
         num_outputs = 0
-        for (i, j, name) in out_indexes(job["command"]):
+        for i, j, name in out_indexes(job["command"]):
             # Trim the {curly brackets} off of the output keys.
             data[name[1:-1]] = outfiles[i]
             num_outputs += 1
diff --git a/js/src/devtools/rootAnalysis/t/sixgill.py b/js/src/devtools/rootAnalysis/t/sixgill.py
index 0b8c2c7073db..307f13fae579 100644
--- a/js/src/devtools/rootAnalysis/t/sixgill.py
+++ b/js/src/devtools/rootAnalysis/t/sixgill.py
@@ -35,7 +35,7 @@ class Body(dict):
             src, dst = edge["Index"]
             self["SrcPoint2Edges"][src].append(edge)
         self["Line2Edges"] = defaultdict(list)
-        for (src, edges) in self["SrcPoint2Edges"].items():
+        for src, edges in self["SrcPoint2Edges"].items():
             line = self["Points"][src]
             self["Line2Edges"][line].extend(edges)
 
diff --git a/js/src/gdb/mozilla/CellHeader.py b/js/src/gdb/mozilla/CellHeader.py
index cb667b3ad0ea..21dcba849d05 100644
--- a/js/src/gdb/mozilla/CellHeader.py
+++ b/js/src/gdb/mozilla/CellHeader.py
@@ -21,5 +21,5 @@ def get_header_length_and_flags(value, cache):
         # If we couldn't fetch the length directly, it must be stored
         # within `flags`.
         length = flags >> 32
-        flags = flags % 2 ** 32
+        flags = flags % 2**32
     return length, flags
diff --git a/js/src/gdb/mozilla/jsval.py b/js/src/gdb/mozilla/jsval.py
index d01a5ceacc41..ffabf6004f16 100644
--- a/js/src/gdb/mozilla/jsval.py
+++ b/js/src/gdb/mozilla/jsval.py
@@ -120,7 +120,7 @@ class JSValueTypeCache(object):
         # the i'th magic value.
         d = gdb.types.make_enum_dict(gdb.lookup_type("JSWhyMagic"))
         self.magic_names = list(range(max(d.values()) + 1))
-        for (k, v) in d.items():
+        for k, v in d.items():
             self.magic_names[v] = k
 
         # Choose an unboxing scheme for this architecture.
diff --git a/js/src/gdb/mozilla/prettyprinters.py b/js/src/gdb/mozilla/prettyprinters.py
index 130e7d847c65..b533d1f1f52f 100644
--- a/js/src/gdb/mozilla/prettyprinters.py
+++ b/js/src/gdb/mozilla/prettyprinters.py
@@ -137,7 +137,7 @@ def clear_module_printers(module_name):
         # should remove. (It's not safe to delete entries from a dictionary
         # while we're iterating over it.)
         to_delete = []
-        for (k, v) in d.items():
+        for k, v in d.items():
             if v.__module__ == module_name:
                 to_delete.append(k)
                 remove_from_subprinter_list(v)
@@ -250,7 +250,6 @@ class TypeCache(object):
 
 
 def implemented_types(t):
-
     # Yield all types that follow |t|.
     def followers(t):
         if t.code == gdb.TYPE_CODE_TYPEDEF:
@@ -346,7 +345,7 @@ def lookup_for_objfile(objfile):
         # to scan the whole list, so regexp printers should be used
         # sparingly.
         s = str(value.type)
-        for (r, f) in printers_by_regexp:
+        for r, f in printers_by_regexp:
             if f.enabled:
                 m = r.match(s)
                 if m:
diff --git a/js/src/gdb/run-tests.py b/js/src/gdb/run-tests.py
index e1d18dc71015..cb9501e90485 100644
--- a/js/src/gdb/run-tests.py
+++ b/js/src/gdb/run-tests.py
@@ -114,7 +114,6 @@ class Summary(object):
             self.bar.finish()
 
         if self.failures:
-
             print("tests failed:")
             for test in self.failures:
                 test.show(sys.stdout)
diff --git a/js/src/tests/lib/jittests.py b/js/src/tests/lib/jittests.py
index 9eaa0bf168dc..060b54f73f04 100755
--- a/js/src/tests/lib/jittests.py
+++ b/js/src/tests/lib/jittests.py
@@ -92,7 +92,6 @@ def extend_condition(condition, value):
 
 
 class JitTest:
-
     VALGRIND_CMD = []
     paths = (d for d in os.environ["PATH"].split(os.pathsep))
     valgrinds = (os.path.join(d, "valgrind") for d in paths)
@@ -488,7 +487,7 @@ def check_output(out, err, rc, timed_out, test, options):
         # Python 3 on Windows interprets process exit codes as unsigned
         # integers, where Python 2 used to allow signed integers. Account for
         # each possibility here.
-        if sys.platform == "win32" and rc in (3 - 2 ** 31, 3 + 2 ** 31):
+        if sys.platform == "win32" and rc in (3 - 2**31, 3 + 2**31):
             return True
 
         if sys.platform != "win32" and rc == -11:
diff --git a/js/src/tests/lib/remote.py b/js/src/tests/lib/remote.py
index 71cedf42ec8a..015a351a3b23 100644
--- a/js/src/tests/lib/remote.py
+++ b/js/src/tests/lib/remote.py
@@ -73,7 +73,7 @@ def init_device(options):
 
             context = MozbuildObject.from_environment()
             adb_path = get_adb_path(context)
-        except (ImportError):
+        except ImportError:
             adb_path = "adb"
 
         DEVICE = ADBDeviceFactory(
diff --git a/js/src/tests/lib/results.py b/js/src/tests/lib/results.py
index f90206035427..9c623b863fbf 100644
--- a/js/src/tests/lib/results.py
+++ b/js/src/tests/lib/results.py
@@ -80,7 +80,7 @@ class TestResult:
                 harness_message = "Exit code reported crash"
             tests = []
         else:
-            for (idx, line) in enumerate(stdout):
+            for idx, line in enumerate(stdout):
                 if line.startswith("WPT OUTPUT: "):
                     msg = line[len("WPT OUTPUT: ") :]
                     data = [output.test.wpt.url] + json.loads(msg)
diff --git a/js/src/tests/lib/tasks_unix.py b/js/src/tests/lib/tasks_unix.py
index bf47695a7f94..36761f30f5a7 100644
--- a/js/src/tests/lib/tasks_unix.py
+++ b/js/src/tests/lib/tasks_unix.py
@@ -118,7 +118,7 @@ def read_input(tasks, timeout):
     try:
         readable, _, _ = select.select(rlist, [], exlist, timeout)
     except OverflowError:
-        print >>sys.stderr, "timeout value", timeout
+        print >> sys.stderr, "timeout value", timeout
         raise
 
     for fd in readable:
diff --git a/js/src/tests/test262-export.py b/js/src/tests/test262-export.py
index ebcb388a29be..477db883ea96 100755
--- a/js/src/tests/test262-export.py
+++ b/js/src/tests/test262-export.py
@@ -299,7 +299,7 @@ def insertMeta(source, frontmatter):
 
     lines.append("/*---")
 
-    for (key, value) in frontmatter.items():
+    for key, value in frontmatter.items():
         if key in ("description", "info"):
             lines.append("%s: |" % key)
             lines.append(
@@ -336,7 +336,6 @@ def findAndCopyIncludes(dirPath, baseDir, includeDir):
     # we reach the base directory of shell.js include files.
     # Each directory will have a shell.js file to copy.
     while relPath:
-
         # find the shell.js
         shellFile = os.path.join(baseDir, relPath, "shell.js")
 
@@ -367,7 +366,6 @@ def findAndCopyIncludes(dirPath, baseDir, includeDir):
 
 
 def exportTest262(args):
-
     outDir = os.path.abspath(args.out)
     providedSrcs = args.src
     includeShell = args.exportshellincludes
@@ -384,15 +382,13 @@ def exportTest262(args):
 
     # Go through each source path
     for providedSrc in providedSrcs:
-
         src = os.path.abspath(providedSrc)
         # the basename of the path will be used in case multiple "src" arguments
         # are passed in to create an output directory for each "src".
         basename = os.path.basename(src)
 
         # Process all test directories recursively.
-        for (dirPath, _, fileNames) in os.walk(src):
-
+        for dirPath, _, fileNames in os.walk(src):
             # we need to make and get the unique set of includes for this filepath
             includes = []
             if includeShell:
diff --git a/js/src/tests/test262-update.py b/js/src/tests/test262-update.py
index 5939c8936775..4027654c3c6c 100755
--- a/js/src/tests/test262-update.py
+++ b/js/src/tests/test262-update.py
@@ -511,7 +511,7 @@ def process_test262(test262Dir, test262OutDir, strictTests, externManifests):
     explicitIncludes[os.path.join("built-ins", "Temporal")] = ["temporalHelpers.js"]
 
     # Process all test directories recursively.
-    for (dirPath, dirNames, fileNames) in os.walk(testDir):
+    for dirPath, dirNames, fileNames in os.walk(testDir):
         relPath = os.path.relpath(dirPath, testDir)
         if relPath == ".":
             continue
@@ -554,7 +554,7 @@ def process_test262(test262Dir, test262OutDir, strictTests, externManifests):
                     test262parser, testSource, testName, includeSet, strictTests
                 )
 
-            for (newFileName, newSource, externRefTest) in convert:
+            for newFileName, newSource, externRefTest in convert:
                 writeTestFile(test262OutDir, newFileName, newSource)
 
                 if externRefTest is not None:
diff --git a/js/src/util/make_unicode.py b/js/src/util/make_unicode.py
index 617268fa9cb7..6ddecd6cbb44 100755
--- a/js/src/util/make_unicode.py
+++ b/js/src/util/make_unicode.py
@@ -202,7 +202,7 @@ def int_ranges(ints):
     """Yields consecutive ranges (inclusive) from integer values."""
     (a, b) = tee(sorted(ints))
     start = next(b)
-    for (curr, succ) in zip_longest(a, b):
+    for curr, succ in zip_longest(a, b):
         if curr + 1 != succ:
             yield (start, curr)
             start = succ
@@ -280,7 +280,7 @@ def process_derived_core_properties(derived_core_properties):
     id_start = set()
     id_continue = set()
 
-    for (char, prop) in read_derived_core_properties(derived_core_properties):
+    for char, prop in read_derived_core_properties(derived_core_properties):
         if prop == "ID_Start":
             id_start.add(char)
         if prop == "ID_Continue":
@@ -399,7 +399,7 @@ def process_case_folding(case_folding):
     folding_tests = []
     folding_codes = set()
 
-    for (code, mapping) in read_case_folding(case_folding):
+    for code, mapping in read_case_folding(case_folding):
         folding_map[code] = mapping
 
         if mapping not in rev_folding_map:
@@ -466,9 +466,7 @@ def process_special_casing(special_casing, table, index):
         (upper, lower, flags) = table[index[code]]
         return ((code + lower) & 0xFFFF, (code + upper) & 0xFFFF)
 
-    for (code, lower, upper, languages, contexts) in read_special_casing(
-        special_casing
-    ):
+    for code, lower, upper, languages, contexts in read_special_casing(special_casing):
         assert code <= MAX_BMP, "Unexpected character outside of BMP: %s" % code
         assert len(languages) <= 1, "Expected zero or one language ids: %s" % languages
         assert len(contexts) <= 1, (
@@ -686,7 +684,7 @@ def write_special_casing_methods(unconditional_toupper, codepoint_table, println
 
     def describe_range(ranges, depth):
         indent = depth * "    "
-        for (start, end) in ranges:
+        for start, end in ranges:
             if start == end:
                 println(indent, "// {}".format(codepoint_table.full_name(start)))
             else:
@@ -715,7 +713,7 @@ def write_special_casing_methods(unconditional_toupper, codepoint_table, println
     def in_any_range(ranges, spaces):
         """Tests if the input character is included in any of the given ranges."""
         lines = [[]]
-        for (start, end) in ranges:
+        for start, end in ranges:
             expr = in_range(start, end, parenthesize=True)
             line = " || ".join(lines[-1] + [expr])
             if len(line) < (100 - len(spaces) - len(" ||")):
@@ -836,9 +834,7 @@ def write_special_casing_methods(unconditional_toupper, codepoint_table, println
         println("{")
 
         println("    switch(ch) {")
-        for (code, converted) in sorted(
-            unconditional_toupper.items(), key=itemgetter(0)
-        ):
+        for code, converted in sorted(unconditional_toupper.items(), key=itemgetter(0)):
             println(
                 "      case {}: return {}; // {}".format(
                     hexlit(code), len(converted), codepoint_table.name(code)
@@ -860,9 +856,7 @@ def write_special_casing_methods(unconditional_toupper, codepoint_table, println
         println("{")
 
         println("    switch(ch) {")
-        for (code, converted) in sorted(
-            unconditional_toupper.items(), key=itemgetter(0)
-        ):
+        for code, converted in sorted(unconditional_toupper.items(), key=itemgetter(0)):
             println(
                 "      case {}: // {}".format(hexlit(code), codepoint_table.name(code))
             )
@@ -1306,7 +1300,7 @@ def make_unicode_file(
         println("bool")
         println("js::unicode::{}(char32_t codePoint)".format(name))
         println("{")
-        for (from_code, to_code) in int_ranges(group_set.keys()):
+        for from_code, to_code in int_ranges(group_set.keys()):
             println(
                 "    if (codePoint >= 0x{:X} && codePoint <= 0x{:X}) {{ // {} .. {}".format(
                     from_code,
@@ -1381,7 +1375,7 @@ def make_unicode_file(
 def getsize(data):
     """return smallest possible integer size for the given array"""
     maxdata = max(data)
-    assert maxdata < 2 ** 32
+    assert maxdata < 2**32
 
     if maxdata < 256:
         return 1
@@ -1421,7 +1415,7 @@ def splitbins(t):
     for shift in range(maxshift + 1):
         t1 = []
         t2 = []
-        size = 2 ** shift
+        size = 2**shift
         bincache = {}
 
         for i in range(0, len(t), size):
@@ -1445,7 +1439,7 @@ def splitbins(t):
     dump(t1, t2, shift, bytes)
 
     # exhaustively verify that the decomposition is correct
-    mask = 2 ** shift - 1
+    mask = 2**shift - 1
     for i in range(len(t)):
         assert t[i] == t2[(t1[i >> shift] << shift) + (i & mask)]
     return best
diff --git a/js/src/vm/jsopcode.py b/js/src/vm/jsopcode.py
index dac69d2f60a5..269ce68dfe3b 100644
--- a/js/src/vm/jsopcode.py
+++ b/js/src/vm/jsopcode.py
@@ -139,7 +139,7 @@ class OpcodeInfo:
 
 
 def find_by_name(list, name):
-    for (n, body) in list:
+    for n, body in list:
         if n == name:
             return body
 
diff --git a/js/src/vm/make_opcode_doc.py b/js/src/vm/make_opcode_doc.py
index 11ce81a3ed59..f84cf63c660f 100755
--- a/js/src/vm/make_opcode_doc.py
+++ b/js/src/vm/make_opcode_doc.py
@@ -165,13 +165,13 @@ def print_doc(index):
         )
     )
 
-    for (category_name, types) in index:
+    for category_name, types in index:
         print(
             '<h3 id="{id}">{name}</h3>'.format(
                 name=category_name, id=make_element_id(category_name)
             )
         )
-        for (type_name, opcodes) in types:
+        for type_name, opcodes in types:
             if type_name:
                 print(
                     '<h4 id="{id}">{name}</h4>'.format(
diff --git a/layout/reftests/border-image/gen-refs.py b/layout/reftests/border-image/gen-refs.py
index 029d46f2a899..1e8bc6c650f9 100644
--- a/layout/reftests/border-image/gen-refs.py
+++ b/layout/reftests/border-image/gen-refs.py
@@ -197,6 +197,7 @@ class Tile:
 # 3 4 5
 # 6 7 8
 
+
 # Compute the source tiles' slice and border-width sizes
 def make_src_tiles():
     tiles = [Tile() for i in range(9)]
diff --git a/layout/reftests/fonts/gsubtest/makegsubfonts.py b/layout/reftests/fonts/gsubtest/makegsubfonts.py
index 73d022e6be2b..8cd6476d9756 100644
--- a/layout/reftests/fonts/gsubtest/makegsubfonts.py
+++ b/layout/reftests/fonts/gsubtest/makegsubfonts.py
@@ -124,7 +124,6 @@ def makeLookup1():
     # build the outline, hmtx and cmap data
     cp = baseCodepoint
     for index, tag in enumerate(features):
-
         # tag.pass
         glyphName = "%s.pass" % tag
         glyphOrder.append(glyphName)
@@ -303,7 +302,6 @@ def makeLookup3():
     # build the outline, hmtx and cmap data
     cp = baseCodepoint
     for index, tag in enumerate(features):
-
         # tag.pass
         glyphName = "%s.pass" % tag
         glyphOrder.append(glyphName)
diff --git a/layout/reftests/fonts/mark-generate.py b/layout/reftests/fonts/mark-generate.py
index 01e2d005480a..85f56a8a2e7f 100755
--- a/layout/reftests/fonts/mark-generate.py
+++ b/layout/reftests/fonts/mark-generate.py
@@ -20,7 +20,7 @@ import fontforge
 # generate a set of fonts, each with our special glyph at one codepoint,
 # and nothing else
 for codepoint in range(ord("A"), ord("D") + 1):
-    for (mark, width) in [("", 1500), ("2", 1800)]:
+    for mark, width in [("", 1500), ("2", 1800)]:
         charname = chr(codepoint)
         f = fontforge.font()
         n = "Mark" + mark + charname
@@ -41,8 +41,8 @@ for codepoint in range(ord("A"), ord("D") + 1):
 
 
 for codepoint in range(ord("A"), ord("A") + 1):
-    for (mark, width) in [("", 1500), ("2", 1800)]:
-        for (uposname, upos) in [("low", -350), ("high", -50)]:
+    for mark, width in [("", 1500), ("2", 1800)]:
+        for uposname, upos in [("low", -350), ("high", -50)]:
             charname = chr(codepoint)
             f = fontforge.font()
             n = "Mark" + mark + charname
diff --git a/layout/style/GenerateCSSPropsGenerated.py b/layout/style/GenerateCSSPropsGenerated.py
index ed2be4fa945f..90ed79219439 100644
--- a/layout/style/GenerateCSSPropsGenerated.py
+++ b/layout/style/GenerateCSSPropsGenerated.py
@@ -62,7 +62,7 @@ def generate(output, dataFile):
         "const int32_t nsCSSProps::"
         "kIDLNameSortPositionTable[eCSSProperty_COUNT] = {\n"
     )
-    for (p, position) in ps:
+    for p, position in ps:
         output.write("  {},\n".format(position))
     output.write("};\n\n")
 
diff --git a/layout/tools/reftest/mach_commands.py b/layout/tools/reftest/mach_commands.py
index bd99ac439365..8cb116433252 100644
--- a/layout/tools/reftest/mach_commands.py
+++ b/layout/tools/reftest/mach_commands.py
@@ -134,7 +134,7 @@ class ReftestRunner(MozbuildObject):
 
         hyphenation_path = os.path.join(self.topsrcdir, "intl", "locales")
 
-        for (dirpath, dirnames, filenames) in os.walk(hyphenation_path):
+        for dirpath, dirnames, filenames in os.walk(hyphenation_path):
             for filename in filenames:
                 if filename.endswith(".dic"):
                     args.extraProfileFiles.append(os.path.join(dirpath, filename))
diff --git a/layout/tools/reftest/runreftest.py b/layout/tools/reftest/runreftest.py
index 36af4acd858b..1c85d2a65b53 100644
--- a/layout/tools/reftest/runreftest.py
+++ b/layout/tools/reftest/runreftest.py
@@ -106,7 +106,6 @@ if sys.version_info[0] == 3:
             raise value_.with_traceback(tb_)
         raise value_
 
-
 else:
     exec("def reraise_(tp_, value_, tb_=None):\n    raise tp_, value_, tb_\n")
 
@@ -652,13 +651,13 @@ class RefTest(object):
         ]
 
         stepResults = {}
-        for (descr, step) in steps:
+        for descr, step in steps:
             stepResults[descr] = "not run / incomplete"
 
         startTime = datetime.now()
         maxTime = timedelta(seconds=options.verify_max_time)
         finalResult = "PASSED"
-        for (descr, step) in steps:
+        for descr, step in steps:
             if (datetime.now() - startTime) > maxTime:
                 self.log.info("::: Test verification is taking too long: Giving up!")
                 self.log.info(
@@ -730,7 +729,7 @@ class RefTest(object):
         # First job is only needs-focus tests.  Remaining jobs are
         # non-needs-focus and chunked.
         perProcessArgs[0].insert(-1, "--focus-filter-mode=needs-focus")
-        for (chunkNumber, jobArgs) in enumerate(perProcessArgs[1:], start=1):
+        for chunkNumber, jobArgs in enumerate(perProcessArgs[1:], start=1):
             jobArgs[-1:-1] = [
                 "--focus-filter-mode=non-needs-focus",
                 "--total-chunks=%d" % jobsWithoutFocus,
@@ -770,16 +769,16 @@ class RefTest(object):
         # Output the summaries that the ReftestThread filters suppressed.
         summaryObjects = [defaultdict(int) for s in summaryLines]
         for t in threads:
-            for (summaryObj, (text, categories)) in zip(summaryObjects, summaryLines):
+            for summaryObj, (text, categories) in zip(summaryObjects, summaryLines):
                 threadMatches = t.summaryMatches[text]
-                for (attribute, description) in categories:
+                for attribute, description in categories:
                     amount = int(threadMatches.group(attribute) if threadMatches else 0)
                     summaryObj[attribute] += amount
                 amount = int(threadMatches.group("total") if threadMatches else 0)
                 summaryObj["total"] += amount
 
         print("REFTEST INFO | Result summary:")
-        for (summaryObj, (text, categories)) in zip(summaryObjects, summaryLines):
+        for summaryObj, (text, categories) in zip(summaryObjects, summaryLines):
             details = ", ".join(
                 [
                     "%d %s" % (summaryObj[attribute], description)
@@ -863,7 +862,6 @@ class RefTest(object):
         valgrindSuppFiles=None,
         **profileArgs
     ):
-
         if cmdargs is None:
             cmdargs = []
         cmdargs = cmdargs[:]
diff --git a/media/highway/moz.build b/media/highway/moz.build
index 67de5725f64a..58b4f96eef1d 100644
--- a/media/highway/moz.build
+++ b/media/highway/moz.build
@@ -9,7 +9,6 @@ LOCAL_INCLUDES += [
 ]
 
 if CONFIG["CPU_ARCH"] == "ppc64" and CONFIG["OS_TARGET"] == "Linux":
-
     DEFINES["TOOLCHAIN_MISS_ASM_HWCAP_H"] = True
 
 SOURCES += [
diff --git a/memory/replace/dmd/dmd.py b/memory/replace/dmd/dmd.py
index ae772d15ff28..3e20d8d6bd94 100755
--- a/memory/replace/dmd/dmd.py
+++ b/memory/replace/dmd/dmd.py
@@ -859,6 +859,7 @@ def prettyPrintDmdJson(out, j):
 # Code for clamping addresses using conservative pointer analysis.
 ##################################################################
 
+
 # Start is the address of the first byte of the block, while end is
 # the address of the first byte after the final byte in the block.
 class AddrRange:
diff --git a/mobile/android/gradle.configure b/mobile/android/gradle.configure
index 09c69e124a6c..557f16c4361e 100644
--- a/mobile/android/gradle.configure
+++ b/mobile/android/gradle.configure
@@ -555,6 +555,7 @@ set_config(
 @imports(_from="itertools", _import="chain")
 def gradle_android_dependencies_tasks(*tasks):
     """Gradle tasks run by |mach android dependencies|."""
+
     # The union, plus a bit more, of all of the Gradle tasks
     # invoked by the android-* automation jobs.
     def withoutGeckoBinaries(task):
diff --git a/mobile/android/mach_commands.py b/mobile/android/mach_commands.py
index b767f10f9a3d..1285095bd4bf 100644
--- a/mobile/android/mach_commands.py
+++ b/mobile/android/mach_commands.py
@@ -329,7 +329,6 @@ def android_geckoview_docs(
     javadoc_path,
     upload_message,
 ):
-
     tasks = (
         command_context.substs["GRADLE_ANDROID_GECKOVIEW_DOCS_ARCHIVE_TASKS"]
         if archive or upload
diff --git a/modules/libpref/test/test_generate_static_pref_list.py b/modules/libpref/test/test_generate_static_pref_list.py
index 2c8797099e65..ef4c9d28caa6 100644
--- a/modules/libpref/test/test_generate_static_pref_list.py
+++ b/modules/libpref/test/test_generate_static_pref_list.py
@@ -479,7 +479,7 @@ class TestGenerateStaticPrefList(unittest.TestCase):
     def test_bad(self):
         "Test various pieces of bad input."
 
-        for (input_string, expected) in bad_inputs:
+        for input_string, expected in bad_inputs:
             inp = StringIO(input_string)
             try:
                 pref_list = yaml.safe_load(inp)
diff --git a/moz.configure b/moz.configure
index a934c814b92a..a970eed3cd4f 100755
--- a/moz.configure
+++ b/moz.configure
@@ -956,7 +956,6 @@ def save_cache(build_environment, configure_cache):
 @imports("glob")
 @imports(_from="os.path", _import="exists")
 def config_status_deps(build_env, build_project):
-
     topsrcdir = build_env.topsrcdir
     topobjdir = build_env.topobjdir
 
diff --git a/mozglue/build/moz.build b/mozglue/build/moz.build
index fe195739e2ee..5ad727554d52 100644
--- a/mozglue/build/moz.build
+++ b/mozglue/build/moz.build
@@ -58,7 +58,6 @@ if CONFIG["OS_TARGET"] == "WINNT":
     ]
 
 if CONFIG["MOZ_WIDGET_TOOLKIT"]:
-
     if CONFIG["MOZ_MEMORY"] and FORCE_SHARED_LIB:
         pass
         # TODO: SHARED_LIBRARY_LIBS go here
diff --git a/python/gdbpp/gdbpp/enumset.py b/python/gdbpp/gdbpp/enumset.py
index c36e863627dd..71315389c1b7 100644
--- a/python/gdbpp/gdbpp/enumset.py
+++ b/python/gdbpp/gdbpp/enumset.py
@@ -21,7 +21,7 @@ class enumset_printer(object):
         return (
             ("flag", gdb.Value(i).cast(self.enum_type))
             for i in range(0, max_bit)
-            if ((bitfield & (2 ** i)) != 0)
+            if ((bitfield & (2**i)) != 0)
         )
 
     def to_string(self):
diff --git a/python/l10n/mozxchannel/projectconfig.py b/python/l10n/mozxchannel/projectconfig.py
index 23d8120a3c5c..85515465417e 100644
--- a/python/l10n/mozxchannel/projectconfig.py
+++ b/python/l10n/mozxchannel/projectconfig.py
@@ -21,23 +21,23 @@ def process_config(toml_content):
     if not new_base:
         new_base = b"."  # relpath to '.' is '', sadly
     base_line = b'\nbasepath = "%s"' % new_base
-    content1 = re.sub(br"^\s*basepath\s*=\s*.+", base_line, toml_content, flags=re.M)
+    content1 = re.sub(rb"^\s*basepath\s*=\s*.+", base_line, toml_content, flags=re.M)
 
     # process [[paths]]
     start = 0
     content2 = b""
     for m in re.finditer(
-        br"\[\[\s*paths\s*\]\].+?(?=\[|\Z)", content1, re.M | re.DOTALL
+        rb"\[\[\s*paths\s*\]\].+?(?=\[|\Z)", content1, re.M | re.DOTALL
     ):
         content2 += content1[start : m.start()]
         path_content = m.group()
-        l10n_line = re.search(br"^\s*l10n\s*=.*$", path_content, flags=re.M).group()
+        l10n_line = re.search(rb"^\s*l10n\s*=.*$", path_content, flags=re.M).group()
         # remove variable expansions
-        new_reference = re.sub(br"{\s*\S+\s*}", b"", l10n_line)
+        new_reference = re.sub(rb"{\s*\S+\s*}", b"", l10n_line)
         # make the l10n a reference line
-        new_reference = re.sub(br"^(\s*)l10n(\s*=)", br"\1reference\2", new_reference)
+        new_reference = re.sub(rb"^(\s*)l10n(\s*=)", rb"\1reference\2", new_reference)
         content2 += re.sub(
-            br"^\s*reference\s*=.*$", new_reference, path_content, flags=re.M
+            rb"^\s*reference\s*=.*$", new_reference, path_content, flags=re.M
         )
         start = m.end()
     content2 += content1[start:]
@@ -45,11 +45,11 @@ def process_config(toml_content):
     start = 0
     content3 = b""
     for m in re.finditer(
-        br"\[\[\s*includes\s*\]\].+?(?=\[|\Z)", content2, re.M | re.DOTALL
+        rb"\[\[\s*includes\s*\]\].+?(?=\[|\Z)", content2, re.M | re.DOTALL
     ):
         content3 += content2[start : m.start()]
         include_content = m.group()
-        m_ = re.search(br'^\s*path = "(.+?)"', include_content, flags=re.M)
+        m_ = re.search(rb'^\s*path = "(.+?)"', include_content, flags=re.M)
         content3 += (
             include_content[: m_.start(1)]
             + generate_filename(m_.group(1))
diff --git a/python/mach/mach/commands/commandinfo.py b/python/mach/mach/commands/commandinfo.py
index 12c4b240ea15..4b5671b035ce 100644
--- a/python/mach/mach/commands/commandinfo.py
+++ b/python/mach/mach/commands/commandinfo.py
@@ -452,7 +452,6 @@ def completion_fish(command_context, outfile):
             cmds_opts.append(comp)
 
         for sub in cmd.subcommands:
-
             for opt_strs, description in sub.options.items():
                 comp = (
                     "complete -c mach -A -n '__fish_mach_complete_subcommand {} {}' "
diff --git a/python/mach/mach/sentry.py b/python/mach/mach/sentry.py
index 5008f8a40cc8..891ab33e665b 100644
--- a/python/mach/mach/sentry.py
+++ b/python/mach/mach/sentry.py
@@ -137,7 +137,7 @@ def _patch_absolute_paths(sentry_event, topsrcdir: Path):
         else:
             return value
 
-    for (target_path, replacement) in (
+    for target_path, replacement in (
         (get_state_dir(), "<statedir>"),
         (str(topsrcdir), "<topsrcdir>"),
         (str(Path.home()), "~"),
diff --git a/python/mozbuild/mozbuild/action/process_install_manifest.py b/python/mozbuild/mozbuild/action/process_install_manifest.py
index faf1376dba96..89b2f89c0170 100644
--- a/python/mozbuild/mozbuild/action/process_install_manifest.py
+++ b/python/mozbuild/mozbuild/action/process_install_manifest.py
@@ -23,7 +23,6 @@ COMPLETE = (
 
 
 def process_manifest(destdir, paths, track, no_symlinks=False, defines={}):
-
     if os.path.exists(track):
         # We use the same format as install manifests for the tracking
         # data.
diff --git a/python/mozbuild/mozbuild/action/tooltool.py b/python/mozbuild/mozbuild/action/tooltool.py
index 350d35a21302..6b53db31e8cc 100755
--- a/python/mozbuild/mozbuild/action/tooltool.py
+++ b/python/mozbuild/mozbuild/action/tooltool.py
@@ -648,7 +648,6 @@ class FileRecordJSONDecoder(json.JSONDecoder):
 
 
 class Manifest(object):
-
     valid_formats = ("json",)
 
     def __init__(self, file_records=None):
diff --git a/python/mozbuild/mozbuild/action/xpccheck.py b/python/mozbuild/mozbuild/action/xpccheck.py
index 4b59577cce96..b576ea4f6486 100644
--- a/python/mozbuild/mozbuild/action/xpccheck.py
+++ b/python/mozbuild/mozbuild/action/xpccheck.py
@@ -62,7 +62,6 @@ def verifyIniFile(initests, directory):
 
         found = False
         for f in files:
-
             fname = f.split("/")[-1]
             if fname.endswith(".in"):
                 fname = ".in".join(fname.split(".in")[:-1])
diff --git a/python/mozbuild/mozbuild/android_version_code.py b/python/mozbuild/mozbuild/android_version_code.py
index aa13609a7a61..3b4025bec758 100644
--- a/python/mozbuild/mozbuild/android_version_code.py
+++ b/python/mozbuild/mozbuild/android_version_code.py
@@ -104,13 +104,13 @@ def android_version_code_v1(buildid, cpu_arch=None, min_sdk=0, max_sdk=0):
             "android:versionCode from build ID %s: hours underflow "
             "bits allotted!" % buildid
         )
-    if base > 2 ** 17:
+    if base > 2**17:
         raise ValueError(
             "Something has gone horribly wrong: cannot calculate "
             "android:versionCode from build ID %s: hours overflow "
             "bits allotted!" % buildid
         )
-    if base > 2 ** 17 - 366 * 24:
+    if base > 2**17 - 366 * 24:
         raise ValueError(
             "Running out of low order bits calculating "
             "android:versionCode from build ID %s: "
diff --git a/python/mozbuild/mozbuild/artifact_commands.py b/python/mozbuild/mozbuild/artifact_commands.py
index 8478c42addff..62406f406ab7 100644
--- a/python/mozbuild/mozbuild/artifact_commands.py
+++ b/python/mozbuild/mozbuild/artifact_commands.py
@@ -513,7 +513,6 @@ def artifact_toolchain(
                 requests.exceptions.ChunkedEncodingError,
                 requests.exceptions.ConnectionError,
             ) as e:
-
                 if isinstance(e, requests.exceptions.HTTPError):
                     # The relengapi proxy likes to return error 400 bad request
                     # which seems improbably to be due to our (simple) GET
diff --git a/python/mozbuild/mozbuild/backend/common.py b/python/mozbuild/mozbuild/backend/common.py
index 784e05e6b9a8..13c241863239 100644
--- a/python/mozbuild/mozbuild/backend/common.py
+++ b/python/mozbuild/mozbuild/backend/common.py
@@ -363,7 +363,6 @@ class CommonBackend(BuildBackend):
         )
 
     def _handle_webidl_collection(self, webidls):
-
         bindings_dir = mozpath.join(self.environment.topobjdir, "dom", "bindings")
 
         all_inputs = set(webidls.all_static_sources())
diff --git a/python/mozbuild/mozbuild/backend/configenvironment.py b/python/mozbuild/mozbuild/backend/configenvironment.py
index eef1b62ee634..770db7333939 100644
--- a/python/mozbuild/mozbuild/backend/configenvironment.py
+++ b/python/mozbuild/mozbuild/backend/configenvironment.py
@@ -121,7 +121,6 @@ class ConfigEnvironment(object):
         source=None,
         mozconfig=None,
     ):
-
         if not source:
             source = mozpath.join(topobjdir, "config.status")
         self.source = source
diff --git a/python/mozbuild/mozbuild/backend/cpp_eclipse.py b/python/mozbuild/mozbuild/backend/cpp_eclipse.py
index 413cca3f753e..f2bd5ecd851e 100644
--- a/python/mozbuild/mozbuild/backend/cpp_eclipse.py
+++ b/python/mozbuild/mozbuild/backend/cpp_eclipse.py
@@ -343,8 +343,8 @@ class CppEclipseBackend(CommonBackend):
             for i in args["includes"]:
                 dirsettings += add_abs_include_path(i)
             for d in args["defines"]:
-                assert d[:2] == u"-D" or d[:2] == u"-U"
-                if d[:2] == u"-U":
+                assert d[:2] == "-D" or d[:2] == "-U"
+                if d[:2] == "-U":
                     # gfx/harfbuzz/src uses -UDEBUG, at least on Mac
                     # netwerk/sctp/src uses -U__APPLE__ on Mac
                     # XXX We should make this code smart enough to remove existing defines.
diff --git a/python/mozbuild/mozbuild/backend/fastermake.py b/python/mozbuild/mozbuild/backend/fastermake.py
index 324db29866d5..c423e00c3240 100644
--- a/python/mozbuild/mozbuild/backend/fastermake.py
+++ b/python/mozbuild/mozbuild/backend/fastermake.py
@@ -225,7 +225,7 @@ class FasterMakeBackend(MakeBackend, PartialBackend):
             mk.create_rule([target]).add_dependencies(
                 "%s" % d[0] for d in sorted(deps, key=itemgetter(0))
             )
-            for (merge, ref_file, l10n_file) in deps:
+            for merge, ref_file, l10n_file in deps:
                 rule = mk.create_rule([merge]).add_dependencies(
                     [ref_file, l10n_file] + python_deps
                 )
diff --git a/python/mozbuild/mozbuild/backend/recursivemake.py b/python/mozbuild/mozbuild/backend/recursivemake.py
index 8cd273032878..2b0a6cb5e9ae 100644
--- a/python/mozbuild/mozbuild/backend/recursivemake.py
+++ b/python/mozbuild/mozbuild/backend/recursivemake.py
@@ -873,7 +873,6 @@ class RecursiveMakeBackend(MakeBackend):
         unified_files_makefile_variable="unified_files",
         include_curdir_build_rules=True,
     ):
-
         # In case it's a generator.
         unified_source_mapping = sorted(unified_source_mapping)
 
diff --git a/python/mozbuild/mozbuild/backend/visualstudio.py b/python/mozbuild/mozbuild/backend/visualstudio.py
index b9b30804b83c..ccf3c65a681d 100644
--- a/python/mozbuild/mozbuild/backend/visualstudio.py
+++ b/python/mozbuild/mozbuild/backend/visualstudio.py
@@ -441,7 +441,6 @@ class VisualStudioBackend(CommonBackend):
     def _create_natvis_type(
         self, doc, visualizer, name, displayString, stringView=None
     ):
-
         t = visualizer.appendChild(doc.createElement("Type"))
         t.setAttribute("Name", name)
 
@@ -593,7 +592,6 @@ class VisualStudioBackend(CommonBackend):
         headers=[],
         sources=[],
     ):
-
         impl = getDOMImplementation()
         doc = impl.createDocument(MSBUILD_NAMESPACE, "Project", None)
 
diff --git a/python/mozbuild/mozbuild/base.py b/python/mozbuild/mozbuild/base.py
index 3f5a6242f838..75eb76b459e5 100644
--- a/python/mozbuild/mozbuild/base.py
+++ b/python/mozbuild/mozbuild/base.py
@@ -751,7 +751,7 @@ class MozbuildObject(ProcessExecutionMixin):
             if not psutil or not job_size:
                 num_jobs = cpus
             else:
-                mem_gb = psutil.virtual_memory().total / 1024 ** 3
+                mem_gb = psutil.virtual_memory().total / 1024**3
                 from_mem = round(mem_gb / job_size)
                 num_jobs = max(1, min(cpus, from_mem))
                 print(
diff --git a/python/mozbuild/mozbuild/code_analysis/mach_commands.py b/python/mozbuild/mozbuild/code_analysis/mach_commands.py
index ad6c3520219f..a65d35c3cfed 100644
--- a/python/mozbuild/mozbuild/code_analysis/mach_commands.py
+++ b/python/mozbuild/mozbuild/code_analysis/mach_commands.py
@@ -99,7 +99,6 @@ class StaticAnalysisMonitor(object):
         self._warnings_database = WarningsDatabase()
 
         def on_warning(warning):
-
             # Output paths relative to repository root if the paths are under repo tree
             warning["filename"] = build_repo_relative_path(
                 warning["filename"], self._srcdir
@@ -542,7 +541,6 @@ def _get_clang_tidy_command(
     jobs,
     fix,
 ):
-
     if checks == "-*":
         checks = ",".join(get_clang_tidy_config(command_context).checks)
 
@@ -786,7 +784,6 @@ def autotest(
                 error_code = ret_val
 
         if error_code != TOOLS_SUCCESS:
-
             command_context.log(
                 logging.INFO,
                 "static-analysis",
@@ -1560,7 +1557,6 @@ def get_clang_tools(
     download_if_needed=True,
     verbose=False,
 ):
-
     rc, clang_paths = _set_clang_tools_paths(command_context)
 
     if rc != 0:
@@ -1803,7 +1799,6 @@ def _copy_clang_format_for_show_diff(
 def _run_clang_format_path(
     command_context, clang_format, paths, output_file, output_format
 ):
-
     # Run clang-format on files or directories directly
     from subprocess import CalledProcessError, check_output
 
diff --git a/python/mozbuild/mozbuild/codecoverage/lcov_rewriter.py b/python/mozbuild/mozbuild/codecoverage/lcov_rewriter.py
index d30c7f68cd5d..6c137a979bc0 100644
--- a/python/mozbuild/mozbuild/codecoverage/lcov_rewriter.py
+++ b/python/mozbuild/mozbuild/codecoverage/lcov_rewriter.py
@@ -42,7 +42,6 @@ class LcovRecord(object):
         self.lines = {}
 
     def __iadd__(self, other):
-
         # These shouldn't differ.
         self.source_file = other.source_file
         if hasattr(other, "test_name"):
diff --git a/python/mozbuild/mozbuild/configure/__init__.py b/python/mozbuild/mozbuild/configure/__init__.py
index 609d17103fae..002b5d6a400e 100644
--- a/python/mozbuild/mozbuild/configure/__init__.py
+++ b/python/mozbuild/mozbuild/configure/__init__.py
@@ -944,7 +944,6 @@ class ConfigureSandbox(dict):
             @imports(_from='mozpack', _import='path', _as='mozpath')
         """
         for value, required in ((_import, True), (_from, False), (_as, False)):
-
             if not isinstance(value, six.string_types) and (
                 required or value is not None
             ):
diff --git a/python/mozbuild/mozbuild/controller/building.py b/python/mozbuild/mozbuild/controller/building.py
index 5a4ef4f39732..aa753bf690c9 100644
--- a/python/mozbuild/mozbuild/controller/building.py
+++ b/python/mozbuild/mozbuild/controller/building.py
@@ -919,8 +919,8 @@ class CCacheStats(object):
     ABSOLUTE_KEYS = {"cache_files", "cache_size", "cache_max_size"}
     FORMAT_KEYS = {"cache_size", "cache_max_size"}
 
-    GiB = 1024 ** 3
-    MiB = 1024 ** 2
+    GiB = 1024**3
+    MiB = 1024**2
     KiB = 1024
 
     def __init__(self, output=None, has_machine_format=False):
diff --git a/python/mozbuild/mozbuild/controller/clobber.py b/python/mozbuild/mozbuild/controller/clobber.py
index 3deba54d756c..e1be2d4bff80 100644
--- a/python/mozbuild/mozbuild/controller/clobber.py
+++ b/python/mozbuild/mozbuild/controller/clobber.py
@@ -80,7 +80,6 @@ class Clobberer(object):
 
         # Object directory clobber older than current is fine.
         if os.path.getmtime(self.src_clobber) <= os.path.getmtime(self.obj_clobber):
-
             return False
 
         return True
@@ -232,7 +231,7 @@ class Clobberer(object):
             self.remove_objdir(False)
             print("Successfully completed auto clobber.", file=fh)
             return True, True, None
-        except (IOError) as error:
+        except IOError as error:
             return (
                 True,
                 False,
diff --git a/python/mozbuild/mozbuild/doctor.py b/python/mozbuild/mozbuild/doctor.py
index 649b50200d48..315a00e7c072 100644
--- a/python/mozbuild/mozbuild/doctor.py
+++ b/python/mozbuild/mozbuild/doctor.py
@@ -231,7 +231,7 @@ def memory(**kwargs) -> DoctorCheck:
     """Check the host machine has the recommended memory to develop Firefox."""
     memory = psutil.virtual_memory().total
     # Convert to gigabytes.
-    memory_GB = memory / 1024 ** 3.0
+    memory_GB = memory / 1024**3.0
     if memory_GB < MEMORY_THRESHOLD:
         status = CheckStatus.WARNING
         desc = "%.1fGB of physical memory, <%.1fGB" % (memory_GB, MEMORY_THRESHOLD)
@@ -266,8 +266,8 @@ def storage_freespace(topsrcdir: str, topobjdir: str, **kwargs) -> List[DoctorCh
         try:
             usage = psutil.disk_usage(mount)
             freespace, size = usage.free, usage.total
-            freespace_GB = freespace / 1024 ** 3
-            size_GB = size / 1024 ** 3
+            freespace_GB = freespace / 1024**3
+            size_GB = size / 1024**3
             if freespace_GB < FREESPACE_THRESHOLD:
                 status = CheckStatus.WARNING
                 desc.append(
diff --git a/python/mozbuild/mozbuild/frontend/context.py b/python/mozbuild/mozbuild/frontend/context.py
index 1e241c56564c..fcc7400bfffd 100644
--- a/python/mozbuild/mozbuild/frontend/context.py
+++ b/python/mozbuild/mozbuild/frontend/context.py
@@ -490,7 +490,6 @@ class LinkFlags(BaseCompileFlags):
                 not self._context.config.substs.get("MOZ_DEBUG"),
             ]
         ):
-
             if self._context.config.substs.get("MOZ_OPTIMIZE"):
                 flags.append("-OPT:REF,ICF")
 
diff --git a/python/mozbuild/mozbuild/frontend/emitter.py b/python/mozbuild/mozbuild/frontend/emitter.py
index f4100772418e..166fe6be798e 100644
--- a/python/mozbuild/mozbuild/frontend/emitter.py
+++ b/python/mozbuild/mozbuild/frontend/emitter.py
@@ -172,7 +172,6 @@ class TreeMetadataEmitter(LoggingMixin):
                 yield o
 
     def _emit_libs_derived(self, contexts):
-
         # First aggregate idl sources.
         webidl_attrs = [
             ("GENERATED_EVENTS_WEBIDL_FILES", lambda c: c.generated_events_sources),
@@ -1461,15 +1460,11 @@ class TreeMetadataEmitter(LoggingMixin):
                 if mozpath.split(base)[0] == "res":
                     has_resources = True
                 for f in files:
-                    if (
-                        var
-                        in (
-                            "FINAL_TARGET_PP_FILES",
-                            "OBJDIR_PP_FILES",
-                            "LOCALIZED_PP_FILES",
-                        )
-                        and not isinstance(f, SourcePath)
-                    ):
+                    if var in (
+                        "FINAL_TARGET_PP_FILES",
+                        "OBJDIR_PP_FILES",
+                        "LOCALIZED_PP_FILES",
+                    ) and not isinstance(f, SourcePath):
                         raise SandboxValidationError(
                             ("Only source directory paths allowed in " + "%s: %s")
                             % (var, f),
@@ -1679,7 +1674,7 @@ class TreeMetadataEmitter(LoggingMixin):
         if not (generated_files or localized_generated_files):
             return
 
-        for (localized, gen) in (
+        for localized, gen in (
             (False, generated_files),
             (True, localized_generated_files),
         ):
diff --git a/python/mozbuild/mozbuild/frontend/reader.py b/python/mozbuild/mozbuild/frontend/reader.py
index 26cdd26f55f0..97a4755dbc53 100644
--- a/python/mozbuild/mozbuild/frontend/reader.py
+++ b/python/mozbuild/mozbuild/frontend/reader.py
@@ -531,7 +531,6 @@ class BuildReaderError(Exception):
         other_error=None,
         sandbox_called_error=None,
     ):
-
         self.file_stack = file_stack
         self.trace = trace
         self.sandbox_called_error = sandbox_called_error
diff --git a/python/mozbuild/mozbuild/gn_processor.py b/python/mozbuild/mozbuild/gn_processor.py
index b6c51ee010a8..8f372363cc80 100644
--- a/python/mozbuild/mozbuild/gn_processor.py
+++ b/python/mozbuild/mozbuild/gn_processor.py
@@ -297,7 +297,6 @@ def process_gn_config(
 
     # Process all targets from the given gn project and its dependencies.
     for target_fullname, spec in six.iteritems(targets):
-
         target_path, target_name = target_info(target_fullname)
         context_attrs = {}
 
@@ -396,7 +395,7 @@ def process_gn_config(
             ".mm": ("CMMFLAGS", ["cflags", "cflags_objcc"]),
         }
         variables = (suffix_map[e] for e in extensions if e in suffix_map)
-        for (var, flag_keys) in variables:
+        for var, flag_keys in variables:
             flags = [
                 _f for _k in flag_keys for _f in spec.get(_k, []) if _f in mozilla_flags
             ]
@@ -522,7 +521,6 @@ def write_mozbuild(
     mozilla_flags,
     write_mozbuild_variables,
 ):
-
     all_mozbuild_results = []
 
     for gn_config in gn_configs:
@@ -626,7 +624,6 @@ def write_mozbuild(
             ("OS_TARGET", "CPU_ARCH"),
             ("OS_TARGET", "CPU_ARCH", "MOZ_X11"),
         ):
-
             conditions = set()
             for args in dirs_by_config.keys():
                 cond = tuple(((k, dict(args).get(k) or "") for k in attrs))
diff --git a/python/mozbuild/mozbuild/jar.py b/python/mozbuild/mozbuild/jar.py
index f7d10f7fed98..1024b6f647a3 100644
--- a/python/mozbuild/mozbuild/jar.py
+++ b/python/mozbuild/mozbuild/jar.py
@@ -98,7 +98,6 @@ class DeprecatedJarManifest(Exception):
 
 
 class JarManifestParser(object):
-
     ignore = re.compile("\s*(\#.*)?$")
     jarline = re.compile(
         """
@@ -210,7 +209,6 @@ class JarMaker(object):
     def __init__(
         self, outputFormat="flat", useJarfileManifest=True, useChromeManifest=False
     ):
-
         self.outputFormat = outputFormat
         self.useJarfileManifest = useJarfileManifest
         self.useChromeManifest = useChromeManifest
diff --git a/python/mozbuild/mozbuild/mach_commands.py b/python/mozbuild/mozbuild/mach_commands.py
index c603195d5d45..6f834965c053 100644
--- a/python/mozbuild/mozbuild/mach_commands.py
+++ b/python/mozbuild/mozbuild/mach_commands.py
@@ -936,7 +936,6 @@ def gtest(
     debugger,
     debugger_args,
 ):
-
     # We lazy build gtest because it's slow to link
     try:
         command_context.config_environment
diff --git a/python/mozbuild/mozbuild/mozconfig.py b/python/mozbuild/mozbuild/mozconfig.py
index 5cb5a5e859d8..960547eb8833 100644
--- a/python/mozbuild/mozbuild/mozconfig.py
+++ b/python/mozbuild/mozbuild/mozconfig.py
@@ -286,7 +286,6 @@ class MozconfigLoader(object):
         in_variable = None
 
         for line in output.splitlines():
-
             if not line:
                 continue
 
diff --git a/python/mozbuild/mozbuild/repackaging/dmg.py b/python/mozbuild/mozbuild/repackaging/dmg.py
index 883927f214d8..5054fdec8e10 100644
--- a/python/mozbuild/mozbuild/repackaging/dmg.py
+++ b/python/mozbuild/mozbuild/repackaging/dmg.py
@@ -13,7 +13,6 @@ from mozbuild.repackaging.application_ini import get_application_ini_value
 
 
 def repackage_dmg(infile, output):
-
     if not tarfile.is_tarfile(infile):
         raise Exception("Input file %s is not a valid tarfile." % infile)
 
diff --git a/python/mozbuild/mozbuild/repackaging/msi.py b/python/mozbuild/mozbuild/repackaging/msi.py
index b0b1b0998329..1884b05afeff 100644
--- a/python/mozbuild/mozbuild/repackaging/msi.py
+++ b/python/mozbuild/mozbuild/repackaging/msi.py
@@ -20,7 +20,6 @@ _MSI_ARCH = {
 
 
 def update_wsx(wfile, pvalues):
-
     parsed = minidom.parse(wfile)
 
     # construct a dictinary for the pre-processing options
diff --git a/python/mozbuild/mozbuild/repackaging/pkg.py b/python/mozbuild/mozbuild/repackaging/pkg.py
index e7699ce5c4a3..c6e276a5d3a7 100644
--- a/python/mozbuild/mozbuild/repackaging/pkg.py
+++ b/python/mozbuild/mozbuild/repackaging/pkg.py
@@ -13,7 +13,6 @@ from mozbuild.bootstrap import bootstrap_toolchain
 
 
 def repackage_pkg(infile, output):
-
     if not tarfile.is_tarfile(infile):
         raise Exception("Input file %s is not a valid tarfile." % infile)
 
diff --git a/python/mozbuild/mozbuild/test/action/test_langpack_manifest.py b/python/mozbuild/mozbuild/test/action/test_langpack_manifest.py
index 29e8642fc745..12750bdd3baf 100644
--- a/python/mozbuild/mozbuild/test/action/test_langpack_manifest.py
+++ b/python/mozbuild/mozbuild/test/action/test_langpack_manifest.py
@@ -154,7 +154,7 @@ langpack-contributors = { "" }
         self.assertEqual(len(description), 132)
 
     def test_get_version_maybe_buildid(self):
-        for (app_version, buildid, expected_version) in [
+        for app_version, buildid, expected_version in [
             ("109", "", "109"),
             ("109.0", "", "109.0"),
             ("109.0.0", "", "109.0.0"),
diff --git a/python/mozbuild/mozbuild/test/backend/test_recursivemake.py b/python/mozbuild/mozbuild/test/backend/test_recursivemake.py
index acbada060b1a..b7b5cd37fab4 100644
--- a/python/mozbuild/mozbuild/test/backend/test_recursivemake.py
+++ b/python/mozbuild/mozbuild/test/backend/test_recursivemake.py
@@ -1292,7 +1292,7 @@ class TestRecursiveMakeBackend(BackendTester):
             ("not-installed", "not-installed.prog"),
         ]
         prefix = "PROGRAM = "
-        for (subdir, expected_program) in expected:
+        for subdir, expected_program in expected:
             with io.open(os.path.join(env.topobjdir, subdir, "backend.mk"), "r") as fh:
                 lines = fh.readlines()
                 program = [
diff --git a/python/mozbuild/mozbuild/test/configure/data/included.configure b/python/mozbuild/mozbuild/test/configure/data/included.configure
index 97166618ec8e..355d41c31a00 100644
--- a/python/mozbuild/mozbuild/test/configure/data/included.configure
+++ b/python/mozbuild/mozbuild/test/configure/data/included.configure
@@ -4,6 +4,7 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
+
 # For more complex and repetitive things, we can create templates
 @template
 def check_compiler_flag(flag):
@@ -18,6 +19,7 @@ def check_compiler_flag(flag):
 
 check_compiler_flag("-Werror=foobar")
 
+
 # Normal functions can be used in @depends functions.
 def fortytwo():
     return 42
@@ -45,6 +47,7 @@ def check(value):
 
 set_config("TEMPLATE_VALUE_2", check)
 
+
 # Normal functions can use @imports too to import modules.
 @imports("sys")
 def platform():
diff --git a/python/mozbuild/mozbuild/test/configure/data/moz.configure b/python/mozbuild/mozbuild/test/configure/data/moz.configure
index 3a7d84b0e3a6..c7fd454eeb4d 100644
--- a/python/mozbuild/mozbuild/test/configure/data/moz.configure
+++ b/python/mozbuild/mozbuild/test/configure/data/moz.configure
@@ -38,6 +38,7 @@ option("--option", env="MOZ_OPTION", help="Option")
 # It is also possible to pass options through the environment only.
 option(env="CC", nargs=1, help="C Compiler")
 
+
 # Call the function when the --enable-simple option is processed, with its
 # OptionValue as argument.
 @depends("--enable-simple")
@@ -48,6 +49,7 @@ def simple(simple):
 
 set_config("ENABLED_SIMPLE", simple)
 
+
 # There can be multiple functions depending on the same option.
 @depends("--enable-simple")
 def simple(simple):
@@ -64,6 +66,7 @@ def with_env(with_env):
 
 set_config("WITH_ENV", with_env)
 
+
 # It doesn't matter if the dependency is on --enable or --disable
 @depends("--disable-values")
 def with_env2(values):
@@ -72,6 +75,7 @@ def with_env2(values):
 
 set_config("VALUES", with_env2)
 
+
 # It is possible to @depends on environment-only options.
 @depends("CC")
 def is_gcc(cc):
@@ -80,6 +84,7 @@ def is_gcc(cc):
 
 set_config("IS_GCC", is_gcc)
 
+
 # It is possible to depend on the result from another function.
 @depends(with_env2)
 def with_env3(values):
@@ -88,6 +93,7 @@ def with_env3(values):
 
 set_config("VALUES2", with_env3)
 
+
 # @depends functions can also return results for use as input to another
 # @depends.
 @depends(with_env3)
@@ -102,6 +108,7 @@ def with_env5(values):
 
 set_config("VALUES3", with_env5)
 
+
 # The result from @depends functions can also be used as input to options.
 # The result must be returned, not implied.
 @depends("--enable-simple")
@@ -195,6 +202,7 @@ include(include_path)
 # decorators.
 option("--with-imports", nargs="?", help="Imports")
 
+
 # A limited set of functions from os.path are exposed by default.
 @depends("--with-imports")
 def with_imports(value):
@@ -204,6 +212,7 @@ def with_imports(value):
 
 set_config("HAS_ABSPATH", with_imports)
 
+
 # It is still possible to import the full set from os.path.
 # It is also possible to cherry-pick builtins.
 @depends("--with-imports")
diff --git a/python/mozbuild/mozbuild/test/configure/test_compile_checks.py b/python/mozbuild/mozbuild/test/configure/test_compile_checks.py
index 37988d535f73..81a4badb9623 100644
--- a/python/mozbuild/mozbuild/test/configure/test_compile_checks.py
+++ b/python/mozbuild/mozbuild/test/configure/test_compile_checks.py
@@ -40,7 +40,6 @@ class BaseCompileChecks(unittest.TestCase):
         return mock_compiler
 
     def do_compile_test(self, command, expected_test_content=None, expected_flags=None):
-
         paths = {
             os.path.abspath("/usr/bin/mockcc"): self.get_mock_compiler(
                 expected_test_content=expected_test_content,
@@ -350,7 +349,6 @@ class TestHeaderChecks(BaseCompileChecks):
         )
 
     def test_check_headers_not_found(self):
-
         cmd = textwrap.dedent(
             """\
             baz_bar, quux_bar = check_headers('baz/foo-bar.h', 'baz-quux/foo-bar.h',
diff --git a/python/mozbuild/mozbuild/test/frontend/test_emitter.py b/python/mozbuild/mozbuild/test/frontend/test_emitter.py
index 2157e69d0aaa..7a68a4323297 100644
--- a/python/mozbuild/mozbuild/test/frontend/test_emitter.py
+++ b/python/mozbuild/mozbuild/test/frontend/test_emitter.py
@@ -1454,7 +1454,6 @@ class TestEmitterBasic(unittest.TestCase):
 
             # Unified sources are not required
             if sources.have_unified_mapping:
-
                 for f in dict(sources.unified_source_mapping).keys():
                     self.assertIn(
                         mozpath.join(
diff --git a/python/mozbuild/mozbuild/testing.py b/python/mozbuild/mozbuild/testing.py
index f951434f9798..ccbe9040b39c 100644
--- a/python/mozbuild/mozbuild/testing.py
+++ b/python/mozbuild/mozbuild/testing.py
@@ -124,7 +124,6 @@ class SupportFilesConverter(object):
         for field, seen in self._fields:
             value = test.get(field, "")
             for pattern in value.split():
-
                 # We track uniqueness locally (per test) where duplicates are forbidden,
                 # and globally, where they are permitted. If a support file appears multiple
                 # times for a single test, there are unnecessary entries in the manifest. But
diff --git a/python/mozlint/mozlint/cli.py b/python/mozlint/mozlint/cli.py
index 02621733677f..d6613eaef300 100644
--- a/python/mozlint/mozlint/cli.py
+++ b/python/mozlint/mozlint/cli.py
@@ -357,7 +357,6 @@ def run(
     result = None
 
     try:
-
         lint.read(linters_info["lint_paths"])
 
         if check_exclude_list:
diff --git a/python/mozlint/test/test_cli.py b/python/mozlint/test/test_cli.py
index 01aeaa74b4b7..2ad12596ebf2 100644
--- a/python/mozlint/test/test_cli.py
+++ b/python/mozlint/test/test_cli.py
@@ -112,7 +112,6 @@ def test_cli_for_exclude_list(run, monkeypatch, capfd):
 
 
 def test_cli_run_with_wrong_linters(run, capfd):
-
     run(["-l", "external", "-l", "foobar"])
     out, err = capfd.readouterr()
 
diff --git a/python/mozperftest/mozperftest/argparser.py b/python/mozperftest/mozperftest/argparser.py
index 3ed5aab64765..bc92afd06084 100644
--- a/python/mozperftest/mozperftest/argparser.py
+++ b/python/mozperftest/mozperftest/argparser.py
@@ -26,7 +26,6 @@ FLAVORS = "desktop-browser", "mobile-browser", "doc", "xpcshell", "webpagetest"
 
 
 class Options:
-
     general_args = {
         "--flavor": {
             "choices": FLAVORS,
diff --git a/python/mozperftest/mozperftest/metrics/notebook/transformer.py b/python/mozperftest/mozperftest/metrics/notebook/transformer.py
index 7ecbc40d8978..b4596d7ca6c8 100644
--- a/python/mozperftest/mozperftest/metrics/notebook/transformer.py
+++ b/python/mozperftest/mozperftest/metrics/notebook/transformer.py
@@ -216,7 +216,7 @@ def get_transformers(dirpath=None):
     for file in tfm_files:
         members = get_transformer(file.resolve().as_posix(), True)
 
-        for (name, tfm_class) in members:
+        for name, tfm_class in members:
             if name in ret:
                 raise NotebookDuplicateTransformsError(
                     f"Duplicated transformer {name} "
diff --git a/python/mozperftest/mozperftest/test/browsertime/runner.py b/python/mozperftest/mozperftest/test/browsertime/runner.py
index 54a9ace44a70..468dcd1a4596 100644
--- a/python/mozperftest/mozperftest/test/browsertime/runner.py
+++ b/python/mozperftest/mozperftest/test/browsertime/runner.py
@@ -148,7 +148,6 @@ class BrowsertimeRunner(NodeRunner):
             "browsertime",
             "package.json",
         ).open() as package:
-
             return json.load(package)
 
     def _get_browsertime_resolved(self):
@@ -362,7 +361,6 @@ class BrowsertimeRunner(NodeRunner):
 
         cycles = self.get_arg("cycles", 1)
         for cycle in range(1, cycles + 1):
-
             # Build an output directory
             output = self.get_arg("output")
             if output is None:
diff --git a/python/mozperftest/mozperftest/test/browsertime/visualtools.py b/python/mozperftest/mozperftest/test/browsertime/visualtools.py
index d25cb131d383..f96a51f7e00f 100644
--- a/python/mozperftest/mozperftest/test/browsertime/visualtools.py
+++ b/python/mozperftest/mozperftest/test/browsertime/visualtools.py
@@ -58,63 +58,108 @@ def get_plat():
 
 
 NUMPY = {
-    ("linux64", "3.10",): (
+    (
+        "linux64",
+        "3.10",
+    ): (
         "88/cc/92815174c345015a326e3fff8beddcb951b3ef0f7c8296fcc22c622add7c"
         "/numpy-1.23.1-cp310-cp310-manylinux_2_17_x86_64.manylinux2014_x86_64.whl"
     ),
-    ("linux64", "3.9",): (
+    (
+        "linux64",
+        "3.9",
+    ): (
         "8d/d6/cc2330e512936a904a4db1629b71d697fb309115f6d2ede94d183cdfe185"
         "/numpy-1.23.1-cp39-cp39-manylinux_2_17_x86_64.manylinux2014_x86_64.whl"
     ),
-    ("linux64", "3.8",): (
+    (
+        "linux64",
+        "3.8",
+    ): (
         "86/c9/9f9d6812fa8a031a568c2c1c49f207a0a4030ead438644c887410fc49c8a"
         "/numpy-1.23.1-cp38-cp38-manylinux_2_17_x86_64.manylinux2014_x86_64.whl"
     ),
-    ("linux64", "3.7",): (
+    (
+        "linux64",
+        "3.7",
+    ): (
         "d6/2e/a2dbcff6f46bb65645d18538d67183a1cf56b006ba96a12575c282a976bc/"
         "numpy-1.19.2-cp37-cp37m-manylinux1_x86_64.whl"
     ),
-    ("linux64", "3.6",): (
+    (
+        "linux64",
+        "3.6",
+    ): (
         "b8/e5/a64ef44a85397ba3c377f6be9c02f3cb3e18023f8c89850dd319e7945521/"
         "numpy-1.19.2-cp36-cp36m-manylinux1_x86_64.whl"
     ),
-    ("darwin", "3.10",): (
+    (
+        "darwin",
+        "3.10",
+    ): (
         "c0/c2/8d58f3ccd1aa3b1eaa5c333a6748e225b45cf8748b13f052cbb3c811c996"
         "/numpy-1.23.1-cp310-cp310-macosx_10_9_x86_64.whl"
     ),
-    ("darwin", "3.9",): (
+    (
+        "darwin",
+        "3.9",
+    ): (
         "e5/43/b1b80cbcea9f2d0e6adadd27a8da2c71b751d5670a846b444087fab408a1"
         "/numpy-1.23.1-cp39-cp39-macosx_10_9_x86_64.whl"
     ),
-    ("darwin", "3.8",): (
+    (
+        "darwin",
+        "3.8",
+    ): (
         "71/08/bc1e4fb7392aa0721f299c444e8c99fa97c8cb41fe33791eca8e26364639"
         "/numpy-1.23.1-cp38-cp38-macosx_10_9_x86_64.whl"
     ),
-    ("darwin", "3.7",): (
+    (
+        "darwin",
+        "3.7",
+    ): (
         "c1/a9/f04a5b7db30cc30b41fe516b8914c5049264490a34a49d977937606fbb23/"
         "numpy-1.19.2-cp37-cp37m-macosx_10_9_x86_64.whl"
     ),
-    ("darwin", "3.6",): (
+    (
+        "darwin",
+        "3.6",
+    ): (
         "be/8e/800113bd3a0c9195b24574b8922ad92be96278028833c389b69a8b14f657/"
         "numpy-1.19.2-cp36-cp36m-macosx_10_9_x86_64.whl"
     ),
-    ("win64", "3.10",): (
+    (
+        "win64",
+        "3.10",
+    ): (
         "8b/11/75a93826457f94a4c857a38ea3f178915f27ff38ffee1753e36994be7810"
         "/numpy-1.23.1-cp310-cp310-win_amd64.whl"
     ),
-    ("win64", "3.9",): (
+    (
+        "win64",
+        "3.9",
+    ): (
         "bd/dd/0610fb49c433fe5987ae312fe672119080fd77be484b5698d6fa7554148b"
         "/numpy-1.23.1-cp39-cp39-win_amd64.whl"
     ),
-    ("win64", "3.8",): (
+    (
+        "win64",
+        "3.8",
+    ): (
         "d0/19/6e81ed6fe30271ebcf25e5e2a0bdf1fa06ddee03a8cb82625503826970db"
         "/numpy-1.23.1-cp38-cp38-win_amd64.whl"
     ),
-    ("win64", "3.7",): (
+    (
+        "win64",
+        "3.7",
+    ): (
         "82/4e/61764556b7ec13f5bd441b04530e2f9f11bb164308ef0e6951919bb846cb/"
         "numpy-1.19.2-cp37-cp37m-win_amd64.whl"
     ),
-    ("win64", "3.6",): (
+    (
+        "win64",
+        "3.6",
+    ): (
         "dc/8e/a78d4e4a28adadbf693a9c056a0d5955a906889fa0dc3768b88deb236e22/"
         "numpy-1.19.2-cp36-cp36m-win_amd64.whl"
     ),
@@ -122,43 +167,73 @@ NUMPY = {
 
 
 SCIPY = {
-    ("linux64", "3.10",): (
+    (
+        "linux64",
+        "3.10",
+    ): (
         "bc/fe/72b611ba221c3367b06163992af4807515d6e0e09b3b9beee8ec22162d6f"
         "/scipy-1.8.1-cp310-cp310-manylinux_2_17_x86_64.manylinux2014_x86_64.whl"
     ),
-    ("linux64", "3.9",): (
+    (
+        "linux64",
+        "3.9",
+    ): (
         "25/82/da07cc3bb40554f1f82d7e24bfa7ffbfb05b50c16eb8d738ebb74b68af8f"
         "/scipy-1.8.1-cp39-cp39-manylinux_2_17_x86_64.manylinux2014_x86_64.whl"
     ),
-    ("linux64", "3.8",): (
+    (
+        "linux64",
+        "3.8",
+    ): (
         "cf/28/5ac0afe5fb473a934ef6bc7953a98a3d2eacf9a8f456524f035f3a844ca4"
         "/scipy-1.8.1-cp38-cp38-manylinux_2_17_x86_64.manylinux2014_x86_64.whl"
     ),
-    ("linux64", "3.7",): (
+    (
+        "linux64",
+        "3.7",
+    ): (
         "65/f9/f7a7e5009711579c72da2725174825e5056741bf4001815d097eef1b2e17"
         "/scipy-1.5.2-cp37-cp37m-manylinux1_x86_64.whl"
     ),
-    ("linux64", "3.6",): (
+    (
+        "linux64",
+        "3.6",
+    ): (
         "2b/a8/f4c66eb529bb252d50e83dbf2909c6502e2f857550f22571ed8556f62d95"
         "/scipy-1.5.2-cp36-cp36m-manylinux1_x86_64.whl"
     ),
-    ("darwin", "3.10",): (
+    (
+        "darwin",
+        "3.10",
+    ): (
         "7c/f3/47b882f8b7a4dbc38e8bc5d7befe3ad2da582ae2229745e1eac77217f3e4"
         "/scipy-1.8.1-cp310-cp310-macosx_10_9_x86_64.whl"
     ),
-    ("darwin", "3.9",): (
+    (
+        "darwin",
+        "3.9",
+    ): (
         "b0/de/e8d273063e1b21ec82e4a09a9654c4dcbc3215abbd59b7038c4ff4272e9e"
         "/scipy-1.8.1-cp39-cp39-macosx_10_9_x86_64.whl"
     ),
-    ("darwin", "3.8",): (
+    (
+        "darwin",
+        "3.8",
+    ): (
         "dd/cc/bb5a9705dd30e7f558358168c793084f80de7cca88b06c82dca9d765b225"
         "/scipy-1.8.1-cp38-cp38-macosx_10_9_x86_64.whl"
     ),
-    ("darwin", "3.7",): (
+    (
+        "darwin",
+        "3.7",
+    ): (
         "bc/47/e71e7f198a0b547fe861520a0240e3171256822dae81fcc97a36b772303e"
         "/scipy-1.5.2-cp37-cp37m-macosx_10_9_x86_64.whl"
     ),
-    ("darwin", "3.6",): (
+    (
+        "darwin",
+        "3.6",
+    ): (
         "00/c0/ddf03baa7ee2a3540d8fbab0fecff7cdd0595dffd91cda746caa95cb686d"
         "/scipy-1.5.2-cp36-cp36m-macosx_10_9_x86_64.whl"
     ),
@@ -174,11 +249,17 @@ SCIPY = {
         "8d/3e/e6f6fa6458e03ecd456ae6178529d4bd610a7c4999189f34d0668e4e69a6"
         "/scipy-1.8.1-cp38-cp38-win_amd64.whl"
     ),
-    ("win64", "3.7",): (
+    (
+        "win64",
+        "3.7",
+    ): (
         "66/80/d8a5050df5b4d8229e018f3222fe603ce7f92c026b78f4e05d69c3a6c43b"
         "/scipy-1.5.2-cp37-cp37m-win_amd64.whl"
     ),
-    ("win64", "3.6",): (
+    (
+        "win64",
+        "3.6",
+    ): (
         "fc/f6/3d455f8b376a0faf1081dbba38bbd594c074292bdec08feaac589f53bc06"
         "/scipy-1.5.2-cp36-cp36m-win_amd64.whl"
     ),
diff --git a/python/mozperftest/mozperftest/tests/conftest.py b/python/mozperftest/mozperftest/tests/conftest.py
index 19435c5369bd..9de1150c9e90 100644
--- a/python/mozperftest/mozperftest/tests/conftest.py
+++ b/python/mozperftest/mozperftest/tests/conftest.py
@@ -143,7 +143,6 @@ def ptnb(standarized_data):
 
 @pytest.fixture(scope="function", autouse=True)
 def perftestetl_plugin():
-
     ret = HERE / "data" / "perftestetl_plugin"
 
     os.environ["PERFTESTETL_PLUGIN"] = ret.resolve().as_posix()
diff --git a/python/mozperftest/mozperftest/tests/test_argparser.py b/python/mozperftest/mozperftest/tests/test_argparser.py
index b65a0809f8c7..35051772b1f4 100644
--- a/python/mozperftest/mozperftest/tests/test_argparser.py
+++ b/python/mozperftest/mozperftest/tests/test_argparser.py
@@ -60,7 +60,6 @@ def test_test_date_today():
 
 
 def test_perfherder_metrics():
-
     parser = PerftestArgumentParser()
     args = [
         "test_one.js",
diff --git a/python/mozperftest/mozperftest/tests/test_notebookupload.py b/python/mozperftest/mozperftest/tests/test_notebookupload.py
index 9defae8ad2c6..0e69f969f3b2 100644
--- a/python/mozperftest/mozperftest/tests/test_notebookupload.py
+++ b/python/mozperftest/mozperftest/tests/test_notebookupload.py
@@ -27,7 +27,6 @@ def setup_env(options):
 @pytest.mark.parametrize("no_filter", [True, False])
 @mock.patch("mozperftest.metrics.notebookupload.PerftestNotebook")
 def test_notebookupload_with_filter(notebook, no_filter):
-
     options = {
         "notebook-metrics": [],
         "notebook-prefix": "",
diff --git a/python/mozperftest/mozperftest/tests/test_perftestnotebook.py b/python/mozperftest/mozperftest/tests/test_perftestnotebook.py
index 55c3acabe178..58debe9343a0 100644
--- a/python/mozperftest/mozperftest/tests/test_perftestnotebook.py
+++ b/python/mozperftest/mozperftest/tests/test_perftestnotebook.py
@@ -26,7 +26,6 @@ def test_get_notebook_section_unknown_analysis(ptnb):
 
 @pytest.mark.parametrize("analysis", [["scatterplot"], None])
 def test_post_to_iodide(ptnb, standarized_data, analysis):
-
     opener = mock.mock_open()
 
     def mocked_open(self, *args, **kwargs):
diff --git a/python/mozperftest/mozperftest/tests/test_utils.py b/python/mozperftest/mozperftest/tests/test_utils.py
index 75c4a431a6e9..013dc0767974 100644
--- a/python/mozperftest/mozperftest/tests/test_utils.py
+++ b/python/mozperftest/mozperftest/tests/test_utils.py
@@ -41,7 +41,7 @@ def test_host_platform():
     if sys.platform.startswith("darwin"):
         assert plat == "darwin"
     else:
-        if sys.maxsize > 2 ** 32:
+        if sys.maxsize > 2**32:
             assert "64" in plat
         else:
             assert "64" not in plat
@@ -166,7 +166,6 @@ class ImportMe:
 
 
 def test_load_class():
-
     with pytest.raises(ImportError):
         load_class("notimportable")
 
diff --git a/python/mozperftest/mozperftest/utils.py b/python/mozperftest/mozperftest/utils.py
index ff2c0b5faa92..3667f683f7bc 100644
--- a/python/mozperftest/mozperftest/utils.py
+++ b/python/mozperftest/mozperftest/utils.py
@@ -90,7 +90,7 @@ def simple_platform():
 
 
 def host_platform():
-    is_64bits = sys.maxsize > 2 ** 32
+    is_64bits = sys.maxsize > 2**32
 
     if sys.platform.startswith("win"):
         if is_64bits:
diff --git a/python/mozrelease/test/test_buglist_creator.py b/python/mozrelease/test/test_buglist_creator.py
index 13a530bb977c..03c76b1d8a05 100644
--- a/python/mozrelease/test/test_buglist_creator.py
+++ b/python/mozrelease/test/test_buglist_creator.py
@@ -117,36 +117,36 @@ def test_parse_tag_version(tag, version):
 def test_get_previous_tag_version(version, tag, previous_tag):
     product = "firefox"
     ff_48_tags = [
-        u"FIREFOX_BETA_48_END",
-        u"FIREFOX_RELEASE_48_END",
-        u"FIREFOX_48_0_2_RELEASE",
-        u"FIREFOX_48_0_2_BUILD1",
-        u"FIREFOX_48_0_1_RELEASE",
-        u"FIREFOX_48_0_1_BUILD3",
-        u"FIREFOX_48_0_RELEASE",
-        u"FIREFOX_48_0_BUILD2",
-        u"FIREFOX_RELEASE_48_BASE",
-        u"FIREFOX_48_0b10_RELEASE",
-        u"FIREFOX_48_0b10_BUILD1",
-        u"FIREFOX_48_0b9_RELEASE",
-        u"FIREFOX_48_0b9_BUILD1",
-        u"FIREFOX_48_0b7_RELEASE",
-        u"FIREFOX_48_0b7_BUILD1",
-        u"FIREFOX_48_0b6_RELEASE",
-        u"FIREFOX_48_0b6_BUILD1",
-        u"FIREFOX_48_0b5_RELEASE",
-        u"FIREFOX_48_0b5_BUILD1",
-        u"FIREFOX_48_0b4_RELEASE",
-        u"FIREFOX_48_0b4_BUILD1",
-        u"FIREFOX_48_0b3_RELEASE",
-        u"FIREFOX_48_0b3_BUILD1",
-        u"FIREFOX_48_0b2_RELEASE",
-        u"FIREFOX_48_0b2_BUILD2",
-        u"FIREFOX_48_0b1_RELEASE",
-        u"FIREFOX_48_0b1_BUILD2",
-        u"FIREFOX_AURORA_48_END",
-        u"FIREFOX_BETA_48_BASE",
-        u"FIREFOX_AURORA_48_BASE",
+        "FIREFOX_BETA_48_END",
+        "FIREFOX_RELEASE_48_END",
+        "FIREFOX_48_0_2_RELEASE",
+        "FIREFOX_48_0_2_BUILD1",
+        "FIREFOX_48_0_1_RELEASE",
+        "FIREFOX_48_0_1_BUILD3",
+        "FIREFOX_48_0_RELEASE",
+        "FIREFOX_48_0_BUILD2",
+        "FIREFOX_RELEASE_48_BASE",
+        "FIREFOX_48_0b10_RELEASE",
+        "FIREFOX_48_0b10_BUILD1",
+        "FIREFOX_48_0b9_RELEASE",
+        "FIREFOX_48_0b9_BUILD1",
+        "FIREFOX_48_0b7_RELEASE",
+        "FIREFOX_48_0b7_BUILD1",
+        "FIREFOX_48_0b6_RELEASE",
+        "FIREFOX_48_0b6_BUILD1",
+        "FIREFOX_48_0b5_RELEASE",
+        "FIREFOX_48_0b5_BUILD1",
+        "FIREFOX_48_0b4_RELEASE",
+        "FIREFOX_48_0b4_BUILD1",
+        "FIREFOX_48_0b3_RELEASE",
+        "FIREFOX_48_0b3_BUILD1",
+        "FIREFOX_48_0b2_RELEASE",
+        "FIREFOX_48_0b2_BUILD2",
+        "FIREFOX_48_0b1_RELEASE",
+        "FIREFOX_48_0b1_BUILD2",
+        "FIREFOX_AURORA_48_END",
+        "FIREFOX_BETA_48_BASE",
+        "FIREFOX_AURORA_48_BASE",
     ]
 
     mock_hg_json = {"tags": [{"tag": ff_48_tag} for ff_48_tag in ff_48_tags]}
@@ -160,18 +160,18 @@ def test_get_bugs_in_changeset():
     bugs, backouts = get_bugs_in_changeset(changeset_data)
 
     assert bugs == {
-        u"1356563",
-        u"1348409",
-        u"1341190",
-        u"1360626",
-        u"1332731",
-        u"1328762",
-        u"1355870",
-        u"1358089",
-        u"1354911",
-        u"1354038",
+        "1356563",
+        "1348409",
+        "1341190",
+        "1360626",
+        "1332731",
+        "1328762",
+        "1355870",
+        "1358089",
+        "1354911",
+        "1354038",
     }
-    assert backouts == {u"1337861", u"1320072"}
+    assert backouts == {"1337861", "1320072"}
 
 
 if __name__ == "__main__":
diff --git a/remote/mach_commands.py b/remote/mach_commands.py
index 35b31a2776d5..7de03c9dfda6 100644
--- a/remote/mach_commands.py
+++ b/remote/mach_commands.py
@@ -634,7 +634,6 @@ def puppeteer_test(
     product="firefox",
     **kwargs,
 ):
-
     logger = mozlog.commandline.setup_logging(
         "puppeteer-test", kwargs, {"mach": sys.stdout}
     )
diff --git a/security/manager/ssl/tests/unit/sign_app.py b/security/manager/ssl/tests/unit/sign_app.py
index a2767c54ebaa..5b57e73c4d18 100755
--- a/security/manager/ssl/tests/unit/sign_app.py
+++ b/security/manager/ssl/tests/unit/sign_app.py
@@ -71,7 +71,7 @@ def coseSignature(payload, algorithm, signingKey, signingCertificate, bodyProtec
     #     external_aad : nil
     #     payload : bstr
     # ]
-    sigStructure = [u"Signature", bodyProtected, protectedEncoded, None, payload]
+    sigStructure = ["Signature", bodyProtected, protectedEncoded, None, payload]
     sigStructureEncoded = dumps(sigStructure)
     pykeyHash = coseAlgorithmToPykeyHash(algorithm)
     signature = signingKey.signRaw(sigStructureEncoded, pykeyHash)
@@ -97,7 +97,7 @@ def coseSig(payload, intermediates, signatures):
     protected = {KID: intermediates}
     protectedEncoded = dumps(protected)
     coseSignatures = []
-    for (algorithm, signingKey, signingCertificate) in signatures:
+    for algorithm, signingKey, signingCertificate in signatures:
         coseSignatures.append(
             coseSignature(
                 payload, algorithm, signingKey, signingCertificate, protectedEncoded
@@ -128,7 +128,7 @@ def addManifestEntry(filename, hashes, contents, entries):
     pairs to use, the contents of the file, and the current list
     of manifest entries."""
     entry = "Name: %s\n" % filename
-    for (hashFunc, name) in hashes:
+    for hashFunc, name in hashes:
         base64hash = b64encode(hashFunc(contents).digest()).decode("ascii")
         entry += "%s-Digest: %s\n" % (name, base64hash)
     entries.append(entry)
@@ -230,7 +230,7 @@ def signZip(
     mfEntries.append("")
 
     with zipfile.ZipFile(outputFile, "w", zipfile.ZIP_DEFLATED) as outZip:
-        for (fullPath, internalPath) in walkDirectory(appDirectory):
+        for fullPath, internalPath in walkDirectory(appDirectory):
             with open(fullPath, "rb") as inputFile:
                 contents = inputFile.read()
             outZip.writestr(internalPath, contents)
@@ -276,7 +276,7 @@ def signZip(
         if len(pkcs7Hashes) != 0 or emptySignerInfos:
             mfContents = "\n".join(mfEntries)
             sfContents = "Signature-Version: 1.0\n"
-            for (hashFunc, name) in signatureHashes:
+            for hashFunc, name in signatureHashes:
                 hashed = hashFunc(six.ensure_binary(mfContents)).digest()
                 base64hash = b64encode(hashed).decode("ascii")
                 sfContents += "%s-Digest-Manifest: %s\n" % (name, base64hash)
diff --git a/servo/components/style/properties/data.py b/servo/components/style/properties/data.py
index 1f3b6536921c..23ead614b9ae 100644
--- a/servo/components/style/properties/data.py
+++ b/servo/components/style/properties/data.py
@@ -733,7 +733,7 @@ class PropertiesData(object):
         # FIXME Servo's DOM architecture doesn't support vendor-prefixed properties.
         #       See servo/servo#14941.
         if self.engine == "gecko":
-            for (prefix, pref) in property.extra_prefixes:
+            for prefix, pref in property.extra_prefixes:
                 property.aliases.append(("-%s-%s" % (prefix, property.name), pref))
 
     def declare_longhand(self, name, engines=None, **kwargs):
diff --git a/taskcluster/gecko_taskgraph/actions/merge_automation.py b/taskcluster/gecko_taskgraph/actions/merge_automation.py
index 8b9455536b68..264383dd66ac 100644
--- a/taskcluster/gecko_taskgraph/actions/merge_automation.py
+++ b/taskcluster/gecko_taskgraph/actions/merge_automation.py
@@ -70,7 +70,6 @@ def is_release_promotion_available(parameters):
     },
 )
 def merge_automation_action(parameters, graph_config, input, task_group_id, task_id):
-
     # make parameters read-write
     parameters = dict(parameters)
 
diff --git a/taskcluster/gecko_taskgraph/actions/retrigger_custom.py b/taskcluster/gecko_taskgraph/actions/retrigger_custom.py
index 677cb00a11b1..bf5365ed7a62 100644
--- a/taskcluster/gecko_taskgraph/actions/retrigger_custom.py
+++ b/taskcluster/gecko_taskgraph/actions/retrigger_custom.py
@@ -164,7 +164,7 @@ def handle_custom_retrigger(parameters, graph_config, input, task_group_id, task
         custom_mach_command += ["--repeat", str(input.get("repeat", 30))]
 
     # add any custom gecko preferences
-    for (key, val) in input.get("preferences", {}).items():
+    for key, val in input.get("preferences", {}).items():
         custom_mach_command += ["--setpref", f"{key}={val}"]
 
     custom_mach_command += [input["path"]]
diff --git a/taskcluster/gecko_taskgraph/docker.py b/taskcluster/gecko_taskgraph/docker.py
index 2927b8302512..f8cbe6ac5fbd 100644
--- a/taskcluster/gecko_taskgraph/docker.py
+++ b/taskcluster/gecko_taskgraph/docker.py
@@ -134,7 +134,6 @@ def load_image(url, imageName=None, imageTag=None):
         req.raise_for_status()
 
         with zstd.ZstdDecompressor().stream_reader(req.raw) as ifh:
-
             tarin = tarfile.open(
                 mode="r|",
                 fileobj=ifh,
diff --git a/taskcluster/gecko_taskgraph/optimize/strategies.py b/taskcluster/gecko_taskgraph/optimize/strategies.py
index 4d0d23a5acf4..35f91fc4f3b1 100644
--- a/taskcluster/gecko_taskgraph/optimize/strategies.py
+++ b/taskcluster/gecko_taskgraph/optimize/strategies.py
@@ -4,17 +4,75 @@
 
 
 import logging
+from datetime import datetime
 
 import mozpack.path as mozpath
 from mozbuild.base import MozbuildObject
 from mozbuild.util import memoize
 from taskgraph.optimize.base import OptimizationStrategy, register_strategy
+from taskgraph.util.taskcluster import find_task_id
 
 from gecko_taskgraph import files_changed
+from gecko_taskgraph.util.taskcluster import status_task
 
 logger = logging.getLogger(__name__)
 
 
+@register_strategy("index-search")
+class IndexSearch(OptimizationStrategy):
+    # A task with no dependencies remaining after optimization will be replaced
+    # if artifacts exist for the corresponding index_paths.
+    # Otherwise, we're in one of the following cases:
+    # - the task has un-optimized dependencies
+    # - the artifacts have expired
+    # - some changes altered the index_paths and new artifacts need to be
+    # created.
+    # In every of those cases, we need to run the task to create or refresh
+    # artifacts.
+
+    fmt = "%Y-%m-%dT%H:%M:%S.%fZ"
+
+    def should_replace_task(self, task, params, deadline, index_paths):
+        "Look for a task with one of the given index paths"
+        for index_path in index_paths:
+            try:
+                task_id = find_task_id(index_path)
+                status = status_task(task_id)
+                # status can be `None` if we're in `testing` mode
+                # (e.g. test-action-callback)
+                if not status or status.get("state") in ("exception", "failed"):
+                    continue
+
+                if deadline and datetime.strptime(
+                    status["expires"], self.fmt
+                ) < datetime.strptime(deadline, self.fmt):
+                    continue
+
+                return task_id
+            except KeyError:
+                # 404 will end up here and go on to the next index path
+                pass
+
+        return False
+
+
+@register_strategy("skip-unless-changed")
+class SkipUnlessChanged(OptimizationStrategy):
+    def should_remove_task(self, task, params, file_patterns):
+        # pushlog_id == -1 - this is the case when run from a cron.yml job
+        if params.get("pushlog_id") == -1:
+            return False
+
+        changed = files_changed.check(params, file_patterns)
+        if not changed:
+            logger.debug(
+                "no files found matching a pattern in `skip-unless-changed` for "
+                + task.label
+            )
+            return True
+        return False
+
+
 @register_strategy("skip-unless-schedules")
 class SkipUnlessSchedules(OptimizationStrategy):
     @memoize
diff --git a/taskcluster/gecko_taskgraph/test/conftest.py b/taskcluster/gecko_taskgraph/test/conftest.py
index 09231c5ab2cb..254db85fe471 100644
--- a/taskcluster/gecko_taskgraph/test/conftest.py
+++ b/taskcluster/gecko_taskgraph/test/conftest.py
@@ -194,7 +194,6 @@ def maketgg(monkeypatch):
 
 @pytest.fixture
 def run_transform():
-
     graph_config = fake_load_graph_config("/root")
     kind = FakeKind.create("fake", {}, graph_config)
 
@@ -208,7 +207,6 @@ def run_transform():
 
 @pytest.fixture
 def run_full_config_transform():
-
     graph_config = fake_load_graph_config("/root")
     kind = FakeKind.create("fullfake", {}, graph_config)
 
diff --git a/taskcluster/gecko_taskgraph/test/test_decision.py b/taskcluster/gecko_taskgraph/test/test_decision.py
index 81be7e0c4428..8440b8e13f59 100644
--- a/taskcluster/gecko_taskgraph/test/test_decision.py
+++ b/taskcluster/gecko_taskgraph/test/test_decision.py
@@ -53,7 +53,6 @@ class TestDecision(unittest.TestCase):
 
 
 class TestGetDecisionParameters(unittest.TestCase):
-
     ttc_file = os.path.join(os.getcwd(), "try_task_config.json")
 
     def setUp(self):
diff --git a/taskcluster/gecko_taskgraph/test/test_util_runnable_jobs.py b/taskcluster/gecko_taskgraph/test/test_util_runnable_jobs.py
index 993521b83002..d1d7b0c06aea 100644
--- a/taskcluster/gecko_taskgraph/test/test_util_runnable_jobs.py
+++ b/taskcluster/gecko_taskgraph/test/test_util_runnable_jobs.py
@@ -14,7 +14,6 @@ from gecko_taskgraph.decision import full_task_graph_to_runnable_jobs
 
 
 class TestRunnableJobs(unittest.TestCase):
-
     tasks = [
         {
             "kind": "build",
diff --git a/taskcluster/gecko_taskgraph/transforms/beetmover_repackage_partner.py b/taskcluster/gecko_taskgraph/transforms/beetmover_repackage_partner.py
index 65b6921cc78f..62215115d647 100644
--- a/taskcluster/gecko_taskgraph/transforms/beetmover_repackage_partner.py
+++ b/taskcluster/gecko_taskgraph/transforms/beetmover_repackage_partner.py
@@ -181,7 +181,6 @@ def generate_upstream_artifacts(
     partner_path,
     repack_stub_installer=False,
 ):
-
     upstream_artifacts = []
     artifact_prefix = get_artifact_prefix(job)
 
diff --git a/taskcluster/gecko_taskgraph/transforms/job/__init__.py b/taskcluster/gecko_taskgraph/transforms/job/__init__.py
index 7ce02c0c72bc..56f3c49e6751 100644
--- a/taskcluster/gecko_taskgraph/transforms/job/__init__.py
+++ b/taskcluster/gecko_taskgraph/transforms/job/__init__.py
@@ -286,7 +286,7 @@ def use_fetches(config, jobs):
         for task in config.kind_dependencies_tasks.values()
         if task.kind in ("fetch", "toolchain")
     )
-    for (kind, task) in tasks:
+    for kind, task in tasks:
         get_attribute(
             artifact_names, task["label"], task["attributes"], f"{kind}-artifact"
         )
diff --git a/taskcluster/gecko_taskgraph/transforms/perftest.py b/taskcluster/gecko_taskgraph/transforms/perftest.py
index 5c579b48b5c7..2eb2a08e7493 100644
--- a/taskcluster/gecko_taskgraph/transforms/perftest.py
+++ b/taskcluster/gecko_taskgraph/transforms/perftest.py
@@ -289,7 +289,6 @@ def setup_perftest_test_date(config, jobs):
 def setup_regression_detector(config, jobs):
     for job in jobs:
         if "change-detector" in job.get("name"):
-
             tasks_to_analyze = []
             for task in config.params["try_task_config"].get("tasks", []):
                 # Explicitly skip these tasks since they're
diff --git a/taskcluster/gecko_taskgraph/transforms/release_msix_push.py b/taskcluster/gecko_taskgraph/transforms/release_msix_push.py
index 817341f92c73..22b356d5a20d 100644
--- a/taskcluster/gecko_taskgraph/transforms/release_msix_push.py
+++ b/taskcluster/gecko_taskgraph/transforms/release_msix_push.py
@@ -38,7 +38,6 @@ transforms.add_validate(push_msix_description_schema)
 @transforms.add
 def make_task_description(config, jobs):
     for job in jobs:
-
         job["worker"]["upstream-artifacts"] = generate_upstream_artifacts(
             job["dependencies"]
         )
diff --git a/taskcluster/gecko_taskgraph/transforms/repackage_signing_partner.py b/taskcluster/gecko_taskgraph/transforms/repackage_signing_partner.py
index 103424074dfa..e3940fd84669 100644
--- a/taskcluster/gecko_taskgraph/transforms/repackage_signing_partner.py
+++ b/taskcluster/gecko_taskgraph/transforms/repackage_signing_partner.py
@@ -58,10 +58,13 @@ def make_repackage_signing_description(config, jobs):
         label = dep_job.label.replace("repackage-", "repackage-signing-")
         # Linux
         label = label.replace("chunking-dummy-", "repackage-signing-")
-        description = "Signing of repackaged artifacts for partner repack id '{repack_id}' for build '" "{build_platform}/{build_type}'".format(  # NOQA: E501
-            repack_id=repack_id,
-            build_platform=attributes.get("build_platform"),
-            build_type=attributes.get("build_type"),
+        description = (
+            "Signing of repackaged artifacts for partner repack id '{repack_id}' for build '"
+            "{build_platform}/{build_type}'".format(  # NOQA: E501
+                repack_id=repack_id,
+                build_platform=attributes.get("build_platform"),
+                build_type=attributes.get("build_type"),
+            )
         )
 
         if "linux" in build_platform:
diff --git a/taskcluster/gecko_taskgraph/transforms/scriptworker_canary.py b/taskcluster/gecko_taskgraph/transforms/scriptworker_canary.py
index 43735f3dcefc..5df2113da3f0 100644
--- a/taskcluster/gecko_taskgraph/transforms/scriptworker_canary.py
+++ b/taskcluster/gecko_taskgraph/transforms/scriptworker_canary.py
@@ -29,7 +29,6 @@ def build_command(config, jobs):
         return
 
     for job in jobs:
-
         command = ["release", "push-scriptworker-canary"]
         for scriptworker in scriptworkers:
             command.extend(["--scriptworker", scriptworker])
diff --git a/taskcluster/gecko_taskgraph/transforms/test/raptor.py b/taskcluster/gecko_taskgraph/transforms/test/raptor.py
index 1e8dad1747cb..f322207f188a 100644
--- a/taskcluster/gecko_taskgraph/transforms/test/raptor.py
+++ b/taskcluster/gecko_taskgraph/transforms/test/raptor.py
@@ -135,7 +135,6 @@ def split_raptor_subtests(config, tests):
             continue
 
         for chunk_number, subtest in enumerate(subtests):
-
             # Create new test job
             chunked = copy_task(test)
             chunked["chunk-number"] = 1 + chunk_number
diff --git a/taskcluster/gecko_taskgraph/transforms/test/variant.py b/taskcluster/gecko_taskgraph/transforms/test/variant.py
index d9e30d9d051a..bda91b2f2567 100644
--- a/taskcluster/gecko_taskgraph/transforms/test/variant.py
+++ b/taskcluster/gecko_taskgraph/transforms/test/variant.py
@@ -60,7 +60,6 @@ def split_variants(config, tasks):
 
         today = datetime.datetime.today()
         for variant in variants:
-
             expiration = variants[variant]["expiration"]
             if len(expiration.split("-")) == 1:
                 continue
diff --git a/taskcluster/gecko_taskgraph/try_option_syntax.py b/taskcluster/gecko_taskgraph/try_option_syntax.py
index cf68a26211f9..9059ad759d25 100644
--- a/taskcluster/gecko_taskgraph/try_option_syntax.py
+++ b/taskcluster/gecko_taskgraph/try_option_syntax.py
@@ -530,10 +530,8 @@ class TryOptionSyntax:
         # This might be somewhat confusing but we parse the string _backwards_ so
         # there is no ambiguity over what state we are in.
         for char in reversed(input_str):
-
             # , indicates exiting a state
             if char == ",":
-
                 # Exit a particular platform.
                 if in_platforms:
                     add_platform(token)
diff --git a/taskcluster/scripts/misc/summarize-tgdiff.py b/taskcluster/scripts/misc/summarize-tgdiff.py
index f3a265ed6614..68db9bbdc7e1 100644
--- a/taskcluster/scripts/misc/summarize-tgdiff.py
+++ b/taskcluster/scripts/misc/summarize-tgdiff.py
@@ -17,7 +17,6 @@ def filter_changes(line):
 
 
 def run():
-
     parser = argparse.ArgumentParser(
         description="Classify output of taskgraph for CI analsyis"
     )
@@ -35,7 +34,6 @@ def run():
 
     out = {"files": {}, "status": "OK", "threshold": args.threshold}
     for path in args.path.glob("*.txt"):
-
         with path.open() as f:
             nb = len(list(filter(filter_changes, f.readlines())))
 
diff --git a/testing/awsy/awsy/parse_about_memory.py b/testing/awsy/awsy/parse_about_memory.py
index 9d86d0e25edc..e98b0e4f9b56 100644
--- a/testing/awsy/awsy/parse_about_memory.py
+++ b/testing/awsy/awsy/parse_about_memory.py
@@ -157,13 +157,13 @@ if __name__ == "__main__":
     totals = calculate_memory_report_values(args.report, args.prefix, args.proc_filter)
 
     sorted_totals = sorted(totals.items(), key=lambda item: (-item[1], item[0]))
-    for (k, v) in sorted_totals:
+    for k, v in sorted_totals:
         if v:
             print("{0}\t".format(k)),
     print("")
 
     bytes_per_mebibyte = 1024.0 * 1024.0
-    for (k, v) in sorted_totals:
+    for k, v in sorted_totals:
         if v:
             if args.mebi:
                 print("{0:.2f} MiB".format(v / bytes_per_mebibyte)),
diff --git a/testing/condprofile/condprof/progress.py b/testing/condprofile/condprof/progress.py
index 764db75074d8..097af53a8ce1 100644
--- a/testing/condprofile/condprof/progress.py
+++ b/testing/condprofile/condprof/progress.py
@@ -206,7 +206,6 @@ def mill(it, label="", hide=None, expected_size=None, every=1):
             if (_i % every) == 0 or (  # True every "every" updates
                 _i == count
             ):  # And when we're done
-
                 STREAM.write(MILL_TEMPLATE % (label, _mill_char(_i), _i, count))
                 STREAM.flush()
 
diff --git a/testing/condprofile/condprof/util.py b/testing/condprofile/condprof/util.py
index 5c09c928a2e5..8f20326b84bf 100644
--- a/testing/condprofile/condprof/util.py
+++ b/testing/condprofile/condprof/util.py
@@ -274,7 +274,6 @@ def extract_from_dmg(dmg, target):
 
 @contextlib.contextmanager
 def latest_nightly(binary=None):
-
     if binary is None:
         # we want to use the latest nightly
         nightly_archive = get_firefox_download_link()
@@ -333,7 +332,7 @@ def get_current_platform():
 
     e.g. macosx64, win32, linux64, etc..
     """
-    arch = sys.maxsize == 2 ** 63 - 1 and "64" or "32"
+    arch = sys.maxsize == 2**63 - 1 and "64" or "32"
     plat = platform.system().lower()
     if plat == "windows":
         plat = "win"
diff --git a/testing/firefox-ui/tests/functional/safebrowsing/test_initial_download.py b/testing/firefox-ui/tests/functional/safebrowsing/test_initial_download.py
index ec973af67484..4013c51d5bff 100644
--- a/testing/firefox-ui/tests/functional/safebrowsing/test_initial_download.py
+++ b/testing/firefox-ui/tests/functional/safebrowsing/test_initial_download.py
@@ -10,7 +10,6 @@ from marionette_harness import MarionetteTestCase
 
 
 class TestSafeBrowsingInitialDownload(MarionetteTestCase):
-
     v2_file_extensions = [
         "vlpset",
         "sbstore",
diff --git a/testing/marionette/client/docs/conf.py b/testing/marionette/client/docs/conf.py
index b388f9864cb1..692545faa942 100644
--- a/testing/marionette/client/docs/conf.py
+++ b/testing/marionette/client/docs/conf.py
@@ -45,8 +45,8 @@ source_suffix = ".rst"
 master_doc = "index"
 
 # General information about the project.
-project = u"Marionette Python Client"
-copyright = u"2013, Mozilla Automation and Tools and individual contributors"
+project = "Marionette Python Client"
+copyright = "2013, Mozilla Automation and Tools and individual contributors"
 
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the
@@ -202,8 +202,8 @@ latex_documents = [
     (
         "index",
         "MarionettePythonClient.tex",
-        u"Marionette Python Client Documentation",
-        u"Mozilla Automation and Tools team",
+        "Marionette Python Client Documentation",
+        "Mozilla Automation and Tools team",
         "manual",
     ),
 ]
@@ -237,8 +237,8 @@ man_pages = [
     (
         "index",
         "marionettepythonclient",
-        u"Marionette Python Client Documentation",
-        [u"Mozilla Automation and Tools team"],
+        "Marionette Python Client Documentation",
+        ["Mozilla Automation and Tools team"],
         1,
     )
 ]
diff --git a/testing/marionette/client/marionette_driver/errors.py b/testing/marionette/client/marionette_driver/errors.py
index 09dc9f24efbd..27e1928a73b0 100644
--- a/testing/marionette/client/marionette_driver/errors.py
+++ b/testing/marionette/client/marionette_driver/errors.py
@@ -39,17 +39,17 @@ class MarionetteException(Exception):
 
         if self.cause:
             if type(self.cause) is tuple:
-                msg += u", caused by {0!r}".format(self.cause[0])
+                msg += ", caused by {0!r}".format(self.cause[0])
                 tb = self.cause[2]
             else:
-                msg += u", caused by {}".format(self.cause)
+                msg += ", caused by {}".format(self.cause)
 
         if self.stacktrace:
-            st = u"".join(["\t{}\n".format(x) for x in self.stacktrace.splitlines()])
-            msg += u"\nstacktrace:\n{}".format(st)
+            st = "".join(["\t{}\n".format(x) for x in self.stacktrace.splitlines()])
+            msg += "\nstacktrace:\n{}".format(st)
 
         if tb:
-            msg += u": " + u"".join(traceback.format_tb(tb))
+            msg += ": " + "".join(traceback.format_tb(tb))
 
         return six.text_type(msg)
 
diff --git a/testing/marionette/client/marionette_driver/geckoinstance.py b/testing/marionette/client/marionette_driver/geckoinstance.py
index e06f1f9728ff..694d47b70f71 100644
--- a/testing/marionette/client/marionette_driver/geckoinstance.py
+++ b/testing/marionette/client/marionette_driver/geckoinstance.py
@@ -261,9 +261,7 @@ class GeckoInstance(object):
             if isinstance(profile_path, six.string_types):
                 profile_args["path_from"] = profile_path
                 profile_args["path_to"] = tempfile.mkdtemp(
-                    suffix=u".{}".format(
-                        profile_name or os.path.basename(profile_path)
-                    ),
+                    suffix=".{}".format(profile_name or os.path.basename(profile_path)),
                     dir=self.workspace,
                 )
                 # The target must not exist yet
@@ -274,7 +272,7 @@ class GeckoInstance(object):
             # Otherwise create a new profile
             else:
                 profile_args["profile"] = tempfile.mkdtemp(
-                    suffix=u".{}".format(profile_name or "mozrunner"),
+                    suffix=".{}".format(profile_name or "mozrunner"),
                     dir=self.workspace,
                 )
                 profile = Profile(**profile_args)
diff --git a/testing/marionette/client/marionette_driver/keys.py b/testing/marionette/client/marionette_driver/keys.py
index c53829b14940..18b547caa737 100644
--- a/testing/marionette/client/marionette_driver/keys.py
+++ b/testing/marionette/client/marionette_driver/keys.py
@@ -19,70 +19,69 @@
 
 
 class Keys(object):
+    NULL = "\ue000"
+    CANCEL = "\ue001"  # ^break
+    HELP = "\ue002"
+    BACK_SPACE = "\ue003"
+    TAB = "\ue004"
+    CLEAR = "\ue005"
+    RETURN = "\ue006"
+    ENTER = "\ue007"
+    SHIFT = "\ue008"
+    LEFT_SHIFT = "\ue008"  # alias
+    CONTROL = "\ue009"
+    LEFT_CONTROL = "\ue009"  # alias
+    ALT = "\ue00a"
+    LEFT_ALT = "\ue00a"  # alias
+    PAUSE = "\ue00b"
+    ESCAPE = "\ue00c"
+    SPACE = "\ue00d"
+    PAGE_UP = "\ue00e"
+    PAGE_DOWN = "\ue00f"
+    END = "\ue010"
+    HOME = "\ue011"
+    LEFT = "\ue012"
+    ARROW_LEFT = "\ue012"  # alias
+    UP = "\ue013"
+    ARROW_UP = "\ue013"  # alias
+    RIGHT = "\ue014"
+    ARROW_RIGHT = "\ue014"  # alias
+    DOWN = "\ue015"
+    ARROW_DOWN = "\ue015"  # alias
+    INSERT = "\ue016"
+    DELETE = "\ue017"
+    SEMICOLON = "\ue018"
+    EQUALS = "\ue019"
 
-    NULL = u"\ue000"
-    CANCEL = u"\ue001"  # ^break
-    HELP = u"\ue002"
-    BACK_SPACE = u"\ue003"
-    TAB = u"\ue004"
-    CLEAR = u"\ue005"
-    RETURN = u"\ue006"
-    ENTER = u"\ue007"
-    SHIFT = u"\ue008"
-    LEFT_SHIFT = u"\ue008"  # alias
-    CONTROL = u"\ue009"
-    LEFT_CONTROL = u"\ue009"  # alias
-    ALT = u"\ue00a"
-    LEFT_ALT = u"\ue00a"  # alias
-    PAUSE = u"\ue00b"
-    ESCAPE = u"\ue00c"
-    SPACE = u"\ue00d"
-    PAGE_UP = u"\ue00e"
-    PAGE_DOWN = u"\ue00f"
-    END = u"\ue010"
-    HOME = u"\ue011"
-    LEFT = u"\ue012"
-    ARROW_LEFT = u"\ue012"  # alias
-    UP = u"\ue013"
-    ARROW_UP = u"\ue013"  # alias
-    RIGHT = u"\ue014"
-    ARROW_RIGHT = u"\ue014"  # alias
-    DOWN = u"\ue015"
-    ARROW_DOWN = u"\ue015"  # alias
-    INSERT = u"\ue016"
-    DELETE = u"\ue017"
-    SEMICOLON = u"\ue018"
-    EQUALS = u"\ue019"
+    NUMPAD0 = "\ue01a"  # numbe pad  keys
+    NUMPAD1 = "\ue01b"
+    NUMPAD2 = "\ue01c"
+    NUMPAD3 = "\ue01d"
+    NUMPAD4 = "\ue01e"
+    NUMPAD5 = "\ue01f"
+    NUMPAD6 = "\ue020"
+    NUMPAD7 = "\ue021"
+    NUMPAD8 = "\ue022"
+    NUMPAD9 = "\ue023"
+    MULTIPLY = "\ue024"
+    ADD = "\ue025"
+    SEPARATOR = "\ue026"
+    SUBTRACT = "\ue027"
+    DECIMAL = "\ue028"
+    DIVIDE = "\ue029"
 
-    NUMPAD0 = u"\ue01a"  # numbe pad  keys
-    NUMPAD1 = u"\ue01b"
-    NUMPAD2 = u"\ue01c"
-    NUMPAD3 = u"\ue01d"
-    NUMPAD4 = u"\ue01e"
-    NUMPAD5 = u"\ue01f"
-    NUMPAD6 = u"\ue020"
-    NUMPAD7 = u"\ue021"
-    NUMPAD8 = u"\ue022"
-    NUMPAD9 = u"\ue023"
-    MULTIPLY = u"\ue024"
-    ADD = u"\ue025"
-    SEPARATOR = u"\ue026"
-    SUBTRACT = u"\ue027"
-    DECIMAL = u"\ue028"
-    DIVIDE = u"\ue029"
+    F1 = "\ue031"  # function  keys
+    F2 = "\ue032"
+    F3 = "\ue033"
+    F4 = "\ue034"
+    F5 = "\ue035"
+    F6 = "\ue036"
+    F7 = "\ue037"
+    F8 = "\ue038"
+    F9 = "\ue039"
+    F10 = "\ue03a"
+    F11 = "\ue03b"
+    F12 = "\ue03c"
 
-    F1 = u"\ue031"  # function  keys
-    F2 = u"\ue032"
-    F3 = u"\ue033"
-    F4 = u"\ue034"
-    F5 = u"\ue035"
-    F6 = u"\ue036"
-    F7 = u"\ue037"
-    F8 = u"\ue038"
-    F9 = u"\ue039"
-    F10 = u"\ue03a"
-    F11 = u"\ue03b"
-    F12 = u"\ue03c"
-
-    META = u"\ue03d"
-    COMMAND = u"\ue03d"
+    META = "\ue03d"
+    COMMAND = "\ue03d"
diff --git a/testing/marionette/client/marionette_driver/transport.py b/testing/marionette/client/marionette_driver/transport.py
index aa63a690233a..cbaac8ea2cd8 100644
--- a/testing/marionette/client/marionette_driver/transport.py
+++ b/testing/marionette/client/marionette_driver/transport.py
@@ -251,7 +251,7 @@ class TcpTransport(object):
                         else:
                             if body_length <= 0:
                                 err = "expected a positive integer"
-                            elif body_length > 2 ** 32 - 1:
+                            elif body_length > 2**32 - 1:
                                 err = "expected a 32 bit integer"
                         if err is not None:
                             raise ValueError(
diff --git a/testing/marionette/harness/marionette_harness/marionette_test/testcases.py b/testing/marionette/harness/marionette_harness/marionette_test/testcases.py
index 32c36967bb91..f1b3233850c6 100644
--- a/testing/marionette/harness/marionette_harness/marionette_test/testcases.py
+++ b/testing/marionette/harness/marionette_harness/marionette_test/testcases.py
@@ -82,7 +82,6 @@ class MetaParameterized(type):
 
 @six.add_metaclass(MetaParameterized)
 class CommonTestCase(unittest.TestCase):
-
     match_re = None
     failureException = AssertionError
     pydebugger = None
@@ -337,7 +336,6 @@ class CommonTestCase(unittest.TestCase):
 
 
 class MarionetteTestCase(CommonTestCase):
-
     match_re = re.compile(r"test_(.*)\.py$")
 
     def __init__(
diff --git a/testing/marionette/harness/marionette_harness/runner/base.py b/testing/marionette/harness/marionette_harness/runner/base.py
index 5ba8a37bd26f..bcfd94d8ef0a 100644
--- a/testing/marionette/harness/marionette_harness/runner/base.py
+++ b/testing/marionette/harness/marionette_harness/runner/base.py
@@ -57,7 +57,6 @@ class MarionetteTest(TestResult):
 
 
 class MarionetteTestResult(StructuredTestResult, TestResultCollection):
-
     resultClass = MarionetteTest
 
     def __init__(self, *args, **kwargs):
@@ -233,7 +232,6 @@ class MarionetteTestResult(StructuredTestResult, TestResultCollection):
 
 
 class MarionetteTextTestRunner(StructuredTestRunner):
-
     resultclass = MarionetteTestResult
 
     def __init__(self, **kwargs):
@@ -603,7 +601,6 @@ class Fixtures(object):
 
 
 class BaseMarionetteTestRunner(object):
-
     textrunnerclass = MarionetteTextTestRunner
     driverclass = Marionette
 
diff --git a/testing/marionette/harness/marionette_harness/tests/harness_unit/conftest.py b/testing/marionette/harness/marionette_harness/tests/harness_unit/conftest.py
index be79f24086de..2fadf225afea 100644
--- a/testing/marionette/harness/marionette_harness/tests/harness_unit/conftest.py
+++ b/testing/marionette/harness/marionette_harness/tests/harness_unit/conftest.py
@@ -35,7 +35,7 @@ def mach_parsed_kwargs(logger):
         "app_args": [],
         "avd": None,
         "avd_home": None,
-        "binary": u"/path/to/firefox",
+        "binary": "/path/to/firefox",
         "browsermob_port": None,
         "browsermob_script": None,
         "device_serial": None,
@@ -72,7 +72,7 @@ def mach_parsed_kwargs(logger):
         "startup_timeout": 60,
         "symbols_path": None,
         "test_tags": None,
-        "tests": [u"/path/to/unit-tests.ini"],
+        "tests": ["/path/to/unit-tests.ini"],
         "testvars": None,
         "this_chunk": None,
         "timeout": None,
diff --git a/testing/marionette/harness/marionette_harness/tests/harness_unit/test_marionette_runner.py b/testing/marionette/harness/marionette_harness/tests/harness_unit/test_marionette_runner.py
index c68a840f792d..2a03d0d03c73 100644
--- a/testing/marionette/harness/marionette_harness/tests/harness_unit/test_marionette_runner.py
+++ b/testing/marionette/harness/marionette_harness/tests/harness_unit/test_marionette_runner.py
@@ -68,7 +68,7 @@ def expected_driver_args(runner):
 
     class ExpectedDict(dict):
         def assert_matches(self, actual):
-            for (k, v) in self.items():
+            for k, v in self.items():
                 assert actual[k] == v
 
         def assert_keys_not_in(self, actual):
@@ -85,7 +85,7 @@ class ManifestFixture:
     def __init__(
         self,
         name="mock_manifest",
-        tests=[{"path": u"test_something.py", "expected": "pass"}],
+        tests=[{"path": "test_something.py", "expected": "pass"}],
     ):
         self.filepath = "/path/to/fake/manifest.ini"
         self.n_disabled = len([t for t in tests if "disabled" in t])
@@ -111,13 +111,13 @@ def manifest_with_tests(request):
     included = []
     if "enabled" in request.param:
         included += [
-            (u"test_expected_pass.py", "pass"),
-            (u"test_expected_fail.py", "fail"),
+            ("test_expected_pass.py", "pass"),
+            ("test_expected_fail.py", "fail"),
         ]
     if "disabled" in request.param:
         included += [
-            (u"test_pass_disabled.py", "pass", "skip-if: true"),
-            (u"test_fail_disabled.py", "fail", "skip-if: true"),
+            ("test_pass_disabled.py", "pass", "skip-if: true"),
+            ("test_fail_disabled.py", "fail", "skip-if: true"),
         ]
     keys = ("path", "expected", "disabled")
     active_tests = [dict(list(zip(keys, values))) for values in included]
@@ -423,12 +423,12 @@ def test_reset_test_stats(mock_runner):
     mock_runner.failed = 1
     mock_runner.failures.append(["TEST-UNEXPECTED-FAIL"])
     assert not reset_successful(mock_runner)
-    mock_runner.run_tests([u"test_fake_thing.py"])
+    mock_runner.run_tests(["test_fake_thing.py"])
     assert reset_successful(mock_runner)
 
 
 def test_initialize_test_run(mock_runner):
-    tests = [u"test_fake_thing.py"]
+    tests = ["test_fake_thing.py"]
     mock_runner.reset_test_stats = Mock()
     mock_runner.run_tests(tests)
     assert mock_runner.reset_test_stats.called
@@ -447,7 +447,7 @@ def test_add_tests(mock_runner):
     fake_tests = ["test_" + i + ".py" for i in "abc"]
     mock_runner.run_tests(fake_tests)
     assert len(mock_runner.tests) == 3
-    for (test_name, added_test) in zip(fake_tests, mock_runner.tests):
+    for test_name, added_test in zip(fake_tests, mock_runner.tests):
         assert added_test["filepath"].endswith(test_name)
 
 
@@ -481,15 +481,15 @@ def test_run_until_failure(mock_runner):
 
 
 def test_catch_invalid_test_names(runner):
-    good_tests = [u"test_ok.py", u"test_is_ok.py"]
+    good_tests = ["test_ok.py", "test_is_ok.py"]
     bad_tests = [
-        u"bad_test.py",
-        u"testbad.py",
-        u"_test_bad.py",
-        u"test_bad.notpy",
-        u"test_bad",
-        u"test.py",
-        u"test_.py",
+        "bad_test.py",
+        "testbad.py",
+        "_test_bad.py",
+        "test_bad.notpy",
+        "test_bad",
+        "test.py",
+        "test_.py",
     ]
     with pytest.raises(Exception) as exc:
         runner._add_tests(good_tests + bad_tests)
diff --git a/testing/marionette/harness/marionette_harness/tests/unit/test_capabilities.py b/testing/marionette/harness/marionette_harness/tests/unit/test_capabilities.py
index b740eedf4636..0cdaf8343f43 100644
--- a/testing/marionette/harness/marionette_harness/tests/unit/test_capabilities.py
+++ b/testing/marionette/harness/marionette_harness/tests/unit/test_capabilities.py
@@ -195,7 +195,7 @@ class TestCapabilityMatching(MarionetteTestCase):
 
         self.delete_session()
 
-        timeouts = {"implicit": 0, "pageLoad": 2.0, "script": 2 ** 53 - 1}
+        timeouts = {"implicit": 0, "pageLoad": 2.0, "script": 2**53 - 1}
         self.marionette.start_session({"timeouts": timeouts})
         self.assertIn("timeouts", self.marionette.session_capabilities)
         self.assertDictEqual(self.marionette.session_capabilities["timeouts"], timeouts)
diff --git a/testing/marionette/harness/marionette_harness/tests/unit/test_crash.py b/testing/marionette/harness/marionette_harness/tests/unit/test_crash.py
index 933a743513cf..b413adda0d1e 100644
--- a/testing/marionette/harness/marionette_harness/tests/unit/test_crash.py
+++ b/testing/marionette/harness/marionette_harness/tests/unit/test_crash.py
@@ -62,7 +62,6 @@ class MockMozCrash(object):
 
 
 class BaseCrashTestCase(MarionetteTestCase):
-
     # Reduce the timeout for faster processing of the tests
     socket_timeout = 10
 
diff --git a/testing/marionette/harness/marionette_harness/tests/unit/test_errors.py b/testing/marionette/harness/marionette_harness/tests/unit/test_errors.py
index 1fb1c888c525..53984dba4849 100644
--- a/testing/marionette/harness/marionette_harness/tests/unit/test_errors.py
+++ b/testing/marionette/harness/marionette_harness/tests/unit/test_errors.py
@@ -19,7 +19,7 @@ def fake_cause():
 
 
 message = "foo"
-unicode_message = u"\u201Cfoo"
+unicode_message = "\u201Cfoo"
 cause = fake_cause()
 stacktrace = "first\nsecond"
 
@@ -93,7 +93,7 @@ class TestLookup(marionette_test.MarionetteTestCase):
 
     def test_by_known_unicode_string(self):
         self.assertEqual(
-            errors.NoSuchElementException, errors.lookup(u"no such element")
+            errors.NoSuchElementException, errors.lookup("no such element")
         )
 
 
diff --git a/testing/marionette/harness/marionette_harness/tests/unit/test_prefs.py b/testing/marionette/harness/marionette_harness/tests/unit/test_prefs.py
index ca9cea3a0da4..c3a66d930a70 100644
--- a/testing/marionette/harness/marionette_harness/tests/unit/test_prefs.py
+++ b/testing/marionette/harness/marionette_harness/tests/unit/test_prefs.py
@@ -174,7 +174,6 @@ class TestPreferences(MarionetteTestCase):
                 pref_not_existent: "existent",
             }
         ):
-
             self.assertTrue(self.marionette.get_pref(self.prefs["bool"]), True)
             self.assertEqual(self.marionette.get_pref(self.prefs["int"]), 24)
             self.assertEqual(self.marionette.get_pref(self.prefs["string"]), "def")
diff --git a/testing/marionette/harness/marionette_harness/tests/unit/test_profile_management.py b/testing/marionette/harness/marionette_harness/tests/unit/test_profile_management.py
index dbe31b29afd6..1420b8815729 100644
--- a/testing/marionette/harness/marionette_harness/tests/unit/test_profile_management.py
+++ b/testing/marionette/harness/marionette_harness/tests/unit/test_profile_management.py
@@ -182,20 +182,20 @@ class TestSwitchProfileWithoutWorkspace(ExternalProfileMixin, BaseProfileManagem
 
     def test_new_named_profile_unicode(self):
         """Test using unicode string with 1-4 bytes encoding works."""
-        self.marionette.instance.switch_profile(u"$¢€🍪")
+        self.marionette.instance.switch_profile("$¢€🍪")
         self.marionette.start_session()
 
         self.assertNotEqual(self.profile_path, self.orig_profile_path)
-        self.assertIn(u"$¢€🍪", self.profile_path)
+        self.assertIn("$¢€🍪", self.profile_path)
         self.assertFalse(os.path.exists(self.orig_profile_path))
 
     def test_new_named_profile_unicode_escape_characters(self):
         """Test using escaped unicode string with 1-4 bytes encoding works."""
-        self.marionette.instance.switch_profile(u"\u0024\u00A2\u20AC\u1F36A")
+        self.marionette.instance.switch_profile("\u0024\u00A2\u20AC\u1F36A")
         self.marionette.start_session()
 
         self.assertNotEqual(self.profile_path, self.orig_profile_path)
-        self.assertIn(u"\u0024\u00A2\u20AC\u1F36A", self.profile_path)
+        self.assertIn("\u0024\u00A2\u20AC\u1F36A", self.profile_path)
         self.assertFalse(os.path.exists(self.orig_profile_path))
 
     def test_clone_existing_profile(self):
diff --git a/testing/marionette/harness/marionette_harness/tests/unit/test_reftest.py b/testing/marionette/harness/marionette_harness/tests/unit/test_reftest.py
index 9e2951e2ea84..e173e5a96324 100644
--- a/testing/marionette/harness/marionette_harness/tests/unit/test_reftest.py
+++ b/testing/marionette/harness/marionette_harness/tests/unit/test_reftest.py
@@ -46,11 +46,11 @@ class TestReftest(MarionetteTestCase):
         )
         self.marionette._send_message("reftest:teardown", {})
         expected = {
-            u"value": {
-                u"extra": {},
-                u"message": u"Testing about:blank == about:blank\n",
-                u"stack": None,
-                u"status": u"PASS",
+            "value": {
+                "extra": {},
+                "message": "Testing about:blank == about:blank\n",
+                "stack": None,
+                "status": "PASS",
             }
         }
         self.assertEqual(expected, rv)
@@ -70,7 +70,7 @@ class TestReftest(MarionetteTestCase):
             },
         )
         self.marionette._send_message("reftest:teardown", {})
-        self.assertEqual(u"PASS", rv[u"value"][u"status"])
+        self.assertEqual("PASS", rv["value"]["status"])
 
     def test_cache_multiple_sizes(self):
         teal = self.fixtures.where_is("reftest/teal-700x700.html")
@@ -88,7 +88,7 @@ class TestReftest(MarionetteTestCase):
                 "height": 600,
             },
         )
-        self.assertEqual(u"PASS", rv[u"value"][u"status"])
+        self.assertEqual("PASS", rv["value"]["status"])
 
         rv = self.marionette._send_message(
             "reftest:run",
@@ -101,5 +101,5 @@ class TestReftest(MarionetteTestCase):
                 "height": 700,
             },
         )
-        self.assertEqual(u"FAIL", rv[u"value"][u"status"])
+        self.assertEqual("FAIL", rv["value"]["status"])
         self.marionette._send_message("reftest:teardown", {})
diff --git a/testing/marionette/harness/marionette_harness/tests/unit/test_skip_setup.py b/testing/marionette/harness/marionette_harness/tests/unit/test_skip_setup.py
index d423567eee13..e3cac5947fc8 100644
--- a/testing/marionette/harness/marionette_harness/tests/unit/test_skip_setup.py
+++ b/testing/marionette/harness/marionette_harness/tests/unit/test_skip_setup.py
@@ -6,7 +6,6 @@ from marionette_harness import MarionetteTestCase, SkipTest
 
 
 class TestSetUpSkipped(MarionetteTestCase):
-
     testVar = {"test": "SkipTest"}
 
     def setUp(self):
@@ -21,7 +20,6 @@ class TestSetUpSkipped(MarionetteTestCase):
 
 
 class TestSetUpNotSkipped(MarionetteTestCase):
-
     testVar = {"test": "SkipTest"}
 
     def setUp(self):
diff --git a/testing/mochitest/bisection.py b/testing/mochitest/bisection.py
index 044be2354216..45c9a0cdf5c6 100644
--- a/testing/mochitest/bisection.py
+++ b/testing/mochitest/bisection.py
@@ -4,7 +4,6 @@ import mozinfo
 
 
 class Bisect(object):
-
     "Class for creating, bisecting and summarizing for --bisect-chunk option."
 
     def __init__(self, harness):
diff --git a/testing/mochitest/runjunit.py b/testing/mochitest/runjunit.py
index 346a116234b5..66df0688c99d 100644
--- a/testing/mochitest/runjunit.py
+++ b/testing/mochitest/runjunit.py
@@ -264,7 +264,7 @@ class JUnitTestRunner(MochitestDesktop):
         for [key, value] in [p.split("=", 1) for p in self.options.add_env]:
             env[key] = value
 
-        for (env_count, (env_key, env_val)) in enumerate(six.iteritems(env)):
+        for env_count, (env_key, env_val) in enumerate(six.iteritems(env)):
             cmd = cmd + " -e env%d %s=%s" % (env_count, env_key, env_val)
         # runner
         cmd = cmd + " %s/%s" % (self.options.app, self.options.runner)
diff --git a/testing/mochitest/runtests.py b/testing/mochitest/runtests.py
index 242550d0eb9a..214f10b08edb 100644
--- a/testing/mochitest/runtests.py
+++ b/testing/mochitest/runtests.py
@@ -442,7 +442,6 @@ if mozinfo.isWin:
         finally:
             ctypes.windll.kernel32.CloseHandle(pHandle)
 
-
 else:
     import errno
 
@@ -473,7 +472,6 @@ else:
 
 
 class MochitestServer(object):
-
     "Web server used to serve Mochitests, for closer fidelity to the real web."
 
     instance_count = 0
@@ -635,7 +633,6 @@ class MochitestServer(object):
 
 
 class WebSocketServer(object):
-
     "Class which encapsulates the mod_pywebsocket server"
 
     def __init__(self, options, scriptdir, logger, debuggerInfo=None):
@@ -1307,7 +1304,7 @@ class MochitestDesktop(object):
             paths.append(test)
 
         # Generate test by schemes
-        for (scheme, grouped_tests) in self.groupTestsByScheme(paths).items():
+        for scheme, grouped_tests in self.groupTestsByScheme(paths).items():
             # Bug 883865 - add this functionality into manifestparser
             with open(
                 os.path.join(SCRIPT_DIR, options.testRunManifestFile), "w"
@@ -3292,13 +3289,13 @@ toolbar#nav-bar {
             ]
 
         stepResults = {}
-        for (descr, step) in steps:
+        for descr, step in steps:
             stepResults[descr] = "not run / incomplete"
 
         startTime = datetime.now()
         maxTime = timedelta(seconds=options.verify_max_time)
         finalResult = "PASSED"
-        for (descr, step) in steps:
+        for descr, step in steps:
             if (datetime.now() - startTime) > maxTime:
                 self.log.info("::: Test verification is taking too long: Giving up!")
                 self.log.info(
@@ -3683,7 +3680,7 @@ toolbar#nav-bar {
 
             # testsToFilter parameter is used to filter out the test list that
             # is sent to getTestsByScheme
-            for (scheme, tests) in self.getTestsByScheme(
+            for scheme, tests in self.getTestsByScheme(
                 options, testsToFilter, True, manifestToFilter
             ):
                 # read the number of tests here, if we are not going to run any,
diff --git a/testing/mozbase/docs/conf.py b/testing/mozbase/docs/conf.py
index dd451e253dc5..7855e250b894 100644
--- a/testing/mozbase/docs/conf.py
+++ b/testing/mozbase/docs/conf.py
@@ -54,8 +54,8 @@ source_suffix = ".rst"
 master_doc = "index"
 
 # General information about the project.
-project = u"MozBase"
-copyright = u"2012, Mozilla Automation and Tools team"
+project = "MozBase"
+copyright = "2012, Mozilla Automation and Tools team"
 
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the
@@ -208,8 +208,8 @@ latex_documents = [
     (
         "index",
         "MozBase.tex",
-        u"MozBase Documentation",
-        u"Mozilla Automation and Tools team",
+        "MozBase Documentation",
+        "Mozilla Automation and Tools team",
         "manual",
     ),
 ]
@@ -243,8 +243,8 @@ man_pages = [
     (
         "index",
         "mozbase",
-        u"MozBase Documentation",
-        [u"Mozilla Automation and Tools team"],
+        "MozBase Documentation",
+        ["Mozilla Automation and Tools team"],
         1,
     )
 ]
@@ -262,8 +262,8 @@ texinfo_documents = [
     (
         "index",
         "MozBase",
-        u"MozBase Documentation",
-        u"Mozilla Automation and Tools team",
+        "MozBase Documentation",
+        "Mozilla Automation and Tools team",
         "MozBase",
         "One line description of project.",
         "Miscellaneous",
diff --git a/testing/mozbase/manifestparser/manifestparser/cli.py b/testing/mozbase/manifestparser/manifestparser/cli.py
index 2fefca33e709..8dd2c3f0cd8d 100644
--- a/testing/mozbase/manifestparser/manifestparser/cli.py
+++ b/testing/mozbase/manifestparser/manifestparser/cli.py
@@ -155,7 +155,6 @@ class WriteCLI(CLICommand):
     usage = "%prog [options] write manifest <manifest> -tag1 -tag2 --key1=value1 --key2=value2 ..."
 
     def __call__(self, options, args):
-
         # parse the arguments
         try:
             kwargs, tags, args = parse_args(args)
diff --git a/testing/mozbase/manifestparser/manifestparser/ini.py b/testing/mozbase/manifestparser/manifestparser/ini.py
index 941f26fa36a3..fb0c56a24a1e 100644
--- a/testing/mozbase/manifestparser/manifestparser/ini.py
+++ b/testing/mozbase/manifestparser/manifestparser/ini.py
@@ -57,8 +57,7 @@ def read_ini(
     current_section = {}
     current_section_name = ""
     key_indent = 0
-    for (linenum, line) in enumerate(fp.read().splitlines(), start=1):
-
+    for linenum, line in enumerate(fp.read().splitlines(), start=1):
         stripped = line.strip()
 
         # ignore blank lines
diff --git a/testing/mozbase/manifestparser/manifestparser/manifestparser.py b/testing/mozbase/manifestparser/manifestparser/manifestparser.py
index 311f54eae866..fe475617ee8b 100644
--- a/testing/mozbase/manifestparser/manifestparser/manifestparser.py
+++ b/testing/mozbase/manifestparser/manifestparser/manifestparser.py
@@ -835,7 +835,6 @@ class ManifestParser(object):
 
         # walk the directories, generating manifests
         def callback(directory, dirpath, dirnames, filenames):
-
             # absolute paths
             filenames = [os.path.join(dirpath, filename) for filename in filenames]
             # ensure new manifest isn't added
diff --git a/testing/mozbase/manifestparser/tests/test_default_overrides.py b/testing/mozbase/manifestparser/tests/test_default_overrides.py
index 0afe9bfdd45a..34140f9447ba 100755
--- a/testing/mozbase/manifestparser/tests/test_default_overrides.py
+++ b/testing/mozbase/manifestparser/tests/test_default_overrides.py
@@ -23,7 +23,6 @@ class TestDefaultSkipif(unittest.TestCase):
     """Tests applying a skip-if condition in [DEFAULT] and || with the value for the test"""
 
     def test_defaults(self):
-
         default = os.path.join(here, "default-skipif.ini")
         parser = ManifestParser(manifests=(default,), use_toml=False)
         for test in parser.tests:
@@ -52,7 +51,6 @@ class TestDefaultSkipif(unittest.TestCase):
                 )
 
     def test_defaults_toml(self):
-
         default = os.path.join(here, "default-skipif.toml")
         parser = ManifestParser(manifests=(default,), use_toml=True)
         for test in parser.tests:
@@ -81,7 +79,6 @@ class TestDefaultSkipif(unittest.TestCase):
                 )
 
     def test_defaults_toml_multiline(self):
-
         default = os.path.join(here, "default-skipif-multiline.toml")
         parser = ManifestParser(manifests=(default,), use_toml=True)
         for test in parser.tests:
@@ -114,7 +111,6 @@ class TestDefaultSupportFiles(unittest.TestCase):
     """Tests combining support-files field in [DEFAULT] with the value for a test"""
 
     def test_defaults(self):
-
         default = os.path.join(here, "default-suppfiles.ini")
         parser = ManifestParser(manifests=(default,), use_toml=False)
         expected_supp_files = {
@@ -127,7 +123,6 @@ class TestDefaultSupportFiles(unittest.TestCase):
             self.assertEqual(test["support-files"], expected)
 
     def test_defaults_toml(self):
-
         default = os.path.join(here, "default-suppfiles.toml")
         parser = ManifestParser(manifests=(default,), use_toml=True)
         expected_supp_files = {
diff --git a/testing/mozbase/manifestparser/tests/test_expressionparser.py b/testing/mozbase/manifestparser/tests/test_expressionparser.py
index 806f2347efb1..2d0eb1be0791 100755
--- a/testing/mozbase/manifestparser/tests/test_expressionparser.py
+++ b/testing/mozbase/manifestparser/tests/test_expressionparser.py
@@ -10,7 +10,6 @@ class ExpressionParserTest(unittest.TestCase):
     """Test the conditional expression parser."""
 
     def test_basic(self):
-
         self.assertEqual(parse("1"), 1)
         self.assertEqual(parse("100"), 100)
         self.assertEqual(parse("true"), True)
@@ -23,7 +22,6 @@ class ExpressionParserTest(unittest.TestCase):
         self.assertEqual(parse("abc123", abc123="xyz"), "xyz")
 
     def test_equality(self):
-
         self.assertTrue(parse("true == true"))
         self.assertTrue(parse("false == false"))
         self.assertTrue(parse("1 == 1"))
diff --git a/testing/mozbase/manifestparser/tests/test_manifestparser.py b/testing/mozbase/manifestparser/tests/test_manifestparser.py
index 708a17172920..ab6cf5d79471 100755
--- a/testing/mozbase/manifestparser/tests/test_manifestparser.py
+++ b/testing/mozbase/manifestparser/tests/test_manifestparser.py
@@ -734,7 +734,6 @@ yellow = submarine
         self.assertFalse("test_0202_app_launch_apply_update_dirlocked.js" in names)
 
     def test_verifyDirectory(self):
-
         directory = os.path.join(here, "verifyDirectory")
 
         # correct manifest
@@ -758,7 +757,6 @@ yellow = submarine
         self.assertEqual(missing, (set([missing_test]), set()))
 
     def test_verifyDirectory_toml(self):
-
         directory = os.path.join(here, "verifyDirectory")
 
         # correct manifest
diff --git a/testing/mozbase/mozcrash/mozcrash/mozcrash.py b/testing/mozbase/mozcrash/mozcrash/mozcrash.py
index 8b5e14caeb20..8adaf7cd11db 100644
--- a/testing/mozbase/mozcrash/mozcrash/mozcrash.py
+++ b/testing/mozbase/mozcrash/mozcrash/mozcrash.py
@@ -768,7 +768,6 @@ if mozinfo.isWin:
                 "kill_pid(): unable to get handle for pid %d: %d" % (pid, err)
             )
 
-
 else:
 
     def kill_pid(pid):
diff --git a/testing/mozbase/mozcrash/tests/conftest.py b/testing/mozbase/mozcrash/tests/conftest.py
index 482751572317..7b6dcea496f6 100644
--- a/testing/mozbase/mozcrash/tests/conftest.py
+++ b/testing/mozbase/mozcrash/tests/conftest.py
@@ -59,7 +59,7 @@ def minidump_files(request, tmpdir):
         extra = tmpdir.join("{}.extra".format(name))
 
         extra.write_text(
-            u"""
+            """
 {
   "ContentSandboxLevel":"2",
   "TelemetryEnvironment":"{🍪}",
@@ -119,7 +119,7 @@ def mock_popen(monkeypatch):
             self.returncode = 0
 
         def communicate(self):
-            return (u"Stackwalk command: {}".format(" ".join(self.args)), "")
+            return ("Stackwalk command: {}".format(" ".join(self.args)), "")
 
         def wait(self):
             return self.returncode
diff --git a/testing/mozbase/mozcrash/tests/test_basic.py b/testing/mozbase/mozcrash/tests/test_basic.py
index 84fb2587eb39..384aba62dcd4 100644
--- a/testing/mozbase/mozcrash/tests/test_basic.py
+++ b/testing/mozbase/mozcrash/tests/test_basic.py
@@ -21,22 +21,22 @@ def test_dump_directory_unicode(request, check_for_crashes, tmpdir, capsys):
     """Test that check_for_crashes can handle unicode in dump_directory."""
     from conftest import minidump_files
 
-    tmpdir = tmpdir.ensure(u"🍪", dir=1)
+    tmpdir = tmpdir.ensure("🍪", dir=1)
     minidump_files = minidump_files(request, tmpdir)
 
     assert 1 == check_for_crashes(dump_directory=fspath(tmpdir), quiet=False)
 
     out, _ = capsys.readouterr()
     assert fspath(minidump_files[0]["dmp"]) in out
-    assert u"🍪" in out
+    assert "🍪" in out
 
 
 def test_test_name_unicode(check_for_crashes, minidump_files, capsys):
     """Test that check_for_crashes can handle unicode in dump_directory."""
-    assert 1 == check_for_crashes(test_name=u"🍪", quiet=False)
+    assert 1 == check_for_crashes(test_name="🍪", quiet=False)
 
     out, err = capsys.readouterr()
-    assert u"| 🍪" in out
+    assert "| 🍪" in out
 
 
 if __name__ == "__main__":
diff --git a/testing/mozbase/mozcrash/tests/test_java_exception.py b/testing/mozbase/mozcrash/tests/test_java_exception.py
index f48ce2cc3ef2..00c8d3c46a32 100644
--- a/testing/mozbase/mozcrash/tests/test_java_exception.py
+++ b/testing/mozbase/mozcrash/tests/test_java_exception.py
@@ -44,7 +44,7 @@ def test_unchecked_exception(check_for_java_exception, test_log):
 
 def test_test_name_unicode(check_for_java_exception, test_log):
     """Test that check_for_crashes can handle unicode in dump_directory."""
-    assert 1 == check_for_java_exception(test_log, test_name=u"🍪", quiet=False)
+    assert 1 == check_for_java_exception(test_log, test_name="🍪", quiet=False)
 
 
 if __name__ == "__main__":
diff --git a/testing/mozbase/mozcrash/tests/test_stackwalk.py b/testing/mozbase/mozcrash/tests/test_stackwalk.py
index 7be2d82c102c..3292e4fdf122 100644
--- a/testing/mozbase/mozcrash/tests/test_stackwalk.py
+++ b/testing/mozbase/mozcrash/tests/test_stackwalk.py
@@ -28,7 +28,7 @@ def test_stackwalk_envvar(check_for_crashes, minidump_files, stackwalk):
 
 def test_stackwalk_unicode(check_for_crashes, minidump_files, tmpdir, capsys):
     """Test that check_for_crashes can handle unicode in dump_directory."""
-    stackwalk = tmpdir.mkdir(u"🍪").join("stackwalk")
+    stackwalk = tmpdir.mkdir("🍪").join("stackwalk")
     stackwalk.write("fake binary")
     stackwalk.chmod(0o744)
 
diff --git a/testing/mozbase/mozcrash/tests/test_symbols_path.py b/testing/mozbase/mozcrash/tests/test_symbols_path.py
index 9aa281bd31fa..644302c947cd 100644
--- a/testing/mozbase/mozcrash/tests/test_symbols_path.py
+++ b/testing/mozbase/mozcrash/tests/test_symbols_path.py
@@ -17,7 +17,7 @@ def test_symbols_path_not_present(check_for_crashes, minidump_files):
 
 def test_symbols_path_unicode(check_for_crashes, minidump_files, tmpdir, capsys):
     """Test that check_for_crashes can handle unicode in dump_directory."""
-    symbols_path = tmpdir.mkdir(u"🍪")
+    symbols_path = tmpdir.mkdir("🍪")
 
     assert 1 == check_for_crashes(symbols_path=fspath(symbols_path), quiet=False)
 
diff --git a/testing/mozbase/mozdevice/mozdevice/adb.py b/testing/mozbase/mozdevice/mozdevice/adb.py
index cf1b78064e20..700a2471fa49 100644
--- a/testing/mozbase/mozdevice/mozdevice/adb.py
+++ b/testing/mozbase/mozdevice/mozdevice/adb.py
@@ -4135,7 +4135,7 @@ class ADBDevice(ADBCommand):
         # against bool prior to testing it against int in order to
         # prevent falsely identifying a bool value as an int.
         if extras:
-            for (key, val) in extras.items():
+            for key, val in extras.items():
                 if isinstance(val, bool):
                     extra_type_param = "--ez"
                 elif isinstance(val, int):
@@ -4196,7 +4196,7 @@ class ADBDevice(ADBCommand):
         if moz_env:
             # moz_env is expected to be a dictionary of environment variables:
             # Fennec itself will set them when launched
-            for (env_count, (env_key, env_val)) in enumerate(moz_env.items()):
+            for env_count, (env_key, env_val) in enumerate(moz_env.items()):
                 extras["env" + str(env_count)] = env_key + "=" + env_val
 
         # Additional command line arguments that fennec will read and use (e.g.
@@ -4261,13 +4261,13 @@ class ADBDevice(ADBCommand):
         if moz_env:
             # moz_env is expected to be a dictionary of environment variables:
             # geckoview_example itself will set them when launched
-            for (env_count, (env_key, env_val)) in enumerate(moz_env.items()):
+            for env_count, (env_key, env_val) in enumerate(moz_env.items()):
                 extras["env" + str(env_count)] = env_key + "=" + env_val
 
         # Additional command line arguments that the app will read and use (e.g.
         # with a custom profile)
         if extra_args:
-            for (arg_count, arg) in enumerate(extra_args):
+            for arg_count, arg in enumerate(extra_args):
                 extras["arg" + str(arg_count)] = arg
 
         extras["use_multiprocess"] = e10s
@@ -4329,13 +4329,13 @@ class ADBDevice(ADBCommand):
         if moz_env:
             # moz_env is expected to be a dictionary of environment variables:
             # geckoview_example itself will set them when launched
-            for (env_count, (env_key, env_val)) in enumerate(moz_env.items()):
+            for env_count, (env_key, env_val) in enumerate(moz_env.items()):
                 extras["env" + str(env_count)] = env_key + "=" + env_val
 
         # Additional command line arguments that the app will read and use (e.g.
         # with a custom profile)
         if extra_args:
-            for (arg_count, arg) in enumerate(extra_args):
+            for arg_count, arg in enumerate(extra_args):
                 extras["arg" + str(arg_count)] = arg
 
         extras["use_multiprocess"] = e10s
diff --git a/testing/mozbase/mozfile/mozfile/mozfile.py b/testing/mozbase/mozfile/mozfile/mozfile.py
index 1f4ffa74af9c..9fd8794ae25c 100644
--- a/testing/mozbase/mozfile/mozfile/mozfile.py
+++ b/testing/mozbase/mozfile/mozfile/mozfile.py
@@ -387,7 +387,6 @@ def tree(directory, sort_key=lambda x: x.lower()):
     top = depth(directory)
 
     for dirpath, dirnames, filenames in os.walk(directory, topdown=True):
-
         abspath = os.path.abspath(dirpath)
         basename = os.path.basename(abspath)
         parent = os.path.dirname(abspath)
@@ -540,7 +539,6 @@ class NamedTemporaryFile(object):
     def __init__(
         self, mode="w+b", bufsize=-1, suffix="", prefix="tmp", dir=None, delete=True
     ):
-
         import tempfile
 
         fd, path = tempfile.mkstemp(suffix, prefix, dir, "t" in mode)
diff --git a/testing/mozbase/mozfile/tests/test_tree.py b/testing/mozbase/mozfile/tests/test_tree.py
index eba7d34a6b1c..556c1b91391b 100644
--- a/testing/mozbase/mozfile/tests/test_tree.py
+++ b/testing/mozbase/mozfile/tests/test_tree.py
@@ -16,12 +16,12 @@ class TestTree(unittest.TestCase):
     def test_unicode_paths(self):
         """Test creating tree structure from a Unicode path."""
         try:
-            tmpdir = tempfile.mkdtemp(suffix=u"tmp🍪")
-            os.mkdir(os.path.join(tmpdir, u"dir🍪"))
-            with open(os.path.join(tmpdir, u"file🍪"), "w") as f:
+            tmpdir = tempfile.mkdtemp(suffix="tmp🍪")
+            os.mkdir(os.path.join(tmpdir, "dir🍪"))
+            with open(os.path.join(tmpdir, "file🍪"), "w") as f:
                 f.write("foo")
 
-            self.assertEqual(u"{}\n├file🍪\n└dir🍪".format(tmpdir), tree(tmpdir))
+            self.assertEqual("{}\n├file🍪\n└dir🍪".format(tmpdir), tree(tmpdir))
         finally:
             shutil.rmtree(tmpdir)
 
diff --git a/testing/mozbase/mozgeckoprofiler/mozgeckoprofiler/symFileManager.py b/testing/mozbase/mozgeckoprofiler/mozgeckoprofiler/symFileManager.py
index e93cbc7b0253..92cfcf323011 100644
--- a/testing/mozbase/mozgeckoprofiler/mozgeckoprofiler/symFileManager.py
+++ b/testing/mozbase/mozgeckoprofiler/mozgeckoprofiler/symFileManager.py
@@ -248,7 +248,7 @@ class SymFileManager:
         self.sCacheLock.acquire()
         try:
             for pdbName in symDirsToInspect:
-                for (mtime, symbolDirPath) in symDirsToInspect[pdbName]:
+                for mtime, symbolDirPath in symDirsToInspect[pdbName]:
                     pdbId = os.path.basename(symbolDirPath)
                     if pdbName in self.sCache and pdbId in self.sCache[pdbName]:
                         symDirsToInspect[pdbName].remove((mtime, symbolDirPath))
@@ -262,7 +262,7 @@ class SymFileManager:
             # The corresponding symbol file name ends with .sym
             symFileName = re.sub(r"\.[^\.]+$", ".sym", pdbName)
 
-            for (mtime, symbolDirPath) in symDirsToInspect[pdbName]:
+            for mtime, symbolDirPath in symDirsToInspect[pdbName]:
                 pdbId = os.path.basename(symbolDirPath)
                 symbolFilePath = symbolDirPath + os.sep + symFileName
                 symbolInfo = self.FetchSymbolsFromFile(symbolFilePath)
@@ -285,7 +285,7 @@ class SymFileManager:
             # Make room for the new symbols
             self.MaybeEvict(fetchedCount)
 
-            for (pdbName, pdbId) in fetchedSymbols:
+            for pdbName, pdbId in fetchedSymbols:
                 if pdbName not in self.sCache:
                     self.sCache[pdbName] = {}
 
@@ -333,7 +333,7 @@ class SymFileManager:
 
         # Evict symbols until evict quota is met, starting with least recently
         # used
-        for (pdbName, pdbId) in reversed(self.sMruSymbols):
+        for pdbName, pdbId in reversed(self.sMruSymbols):
             if numToEvict <= 0:
                 break
 
diff --git a/testing/mozbase/mozgeckoprofiler/tests/test_view_gecko_profiler.py b/testing/mozbase/mozgeckoprofiler/tests/test_view_gecko_profiler.py
index c22b16fe1840..76dd0f4594f8 100644
--- a/testing/mozbase/mozgeckoprofiler/tests/test_view_gecko_profiler.py
+++ b/testing/mozbase/mozgeckoprofiler/tests/test_view_gecko_profiler.py
@@ -52,12 +52,11 @@ class TestViewGeckoProfile(unittest.TestCase):
         self.response = [None]
 
     def test_view_gecko_profile(self):
-
         # Create a temporary fake performance profile.
         temp_dir = tempfile.mkdtemp()
         profile_path = os.path.join(temp_dir, "fakeprofile.json")
         with io.open(profile_path, "w") as f:
-            f.write(u"FAKE_PROFILE")
+            f.write("FAKE_PROFILE")
 
         # Mock the open_new_tab function so that we know when the view_gecko_profile
         # function has done all of its work, and we can assert ressult of the
diff --git a/testing/mozbase/mozhttpd/mozhttpd/mozhttpd.py b/testing/mozbase/mozhttpd/mozhttpd/mozhttpd.py
index 91066c0deb96..dd4e606a5553 100755
--- a/testing/mozbase/mozhttpd/mozhttpd/mozhttpd.py
+++ b/testing/mozbase/mozhttpd/mozhttpd/mozhttpd.py
@@ -67,7 +67,6 @@ class Request(object):
 
 
 class RequestHandler(SimpleHTTPRequestHandler):
-
     docroot = os.getcwd()  # current working directory at time of import
     proxy_host_dirs = False
     request_log = []
@@ -94,7 +93,7 @@ class RequestHandler(SimpleHTTPRequestHandler):
                     self.request, *m.groups()
                 )
                 self.send_response(response_code)
-                for (keyword, value) in iteritems(headerdict):
+                for keyword, value in iteritems(headerdict):
                     self.send_header(keyword, value)
                 self.end_headers()
                 self.wfile.write(ensure_binary(data))
diff --git a/testing/mozbase/mozinfo/mozinfo/mozinfo.py b/testing/mozbase/mozinfo/mozinfo/mozinfo.py
index e1fffbb5fc39..0736356e197a 100755
--- a/testing/mozbase/mozinfo/mozinfo/mozinfo.py
+++ b/testing/mozbase/mozinfo/mozinfo/mozinfo.py
@@ -349,7 +349,6 @@ __all__ += [
 
 
 def main(args=None):
-
     # parse the command line
     from optparse import OptionParser
 
diff --git a/testing/mozbase/mozinfo/tests/test.py b/testing/mozbase/mozinfo/tests/test.py
index 14e516b7fcb1..f1d971d3179a 100644
--- a/testing/mozbase/mozinfo/tests/test.py
+++ b/testing/mozbase/mozinfo/tests/test.py
@@ -164,8 +164,8 @@ def test_compare_to_string():
     assert b > a
 
     # Make sure we can compare against unicode (for python 2).
-    assert a == u"1.2.5a"
-    assert u"1.2.5a" == a
+    assert a == "1.2.5a"
+    assert "1.2.5a" == a
 
 
 def test_to_string():
diff --git a/testing/mozbase/mozlog/mozlog/formatters/grouping.py b/testing/mozbase/mozlog/mozlog/formatters/grouping.py
index 36993b5595ef..89f5d2478315 100644
--- a/testing/mozbase/mozlog/mozlog/formatters/grouping.py
+++ b/testing/mozbase/mozlog/mozlog/formatters/grouping.py
@@ -11,8 +11,8 @@ import six
 
 from mozlog.formatters import base
 
-DEFAULT_MOVE_UP_CODE = u"\x1b[A"
-DEFAULT_CLEAR_EOL_CODE = u"\x1b[K"
+DEFAULT_MOVE_UP_CODE = "\x1b[A"
+DEFAULT_CLEAR_EOL_CODE = "\x1b[K"
 
 
 class GroupingFormatter(base.BaseFormatter):
@@ -145,11 +145,11 @@ class GroupingFormatter(base.BaseFormatter):
         self.start_time = data["time"]
 
         if self.number_of_tests == 0:
-            return "Running tests in %s\n\n" % data[u"source"]
+            return "Running tests in %s\n\n" % data["source"]
         else:
             return "Running %i tests in %s\n\n" % (
                 self.number_of_tests,
-                data[u"source"],
+                data["source"],
             )
 
     def test_start(self, data):
@@ -159,11 +159,11 @@ class GroupingFormatter(base.BaseFormatter):
     def wrap_and_indent_lines(self, lines, indent):
         assert len(lines) > 0
 
-        output = indent + u"\u25B6 %s\n" % lines[0]
+        output = indent + "\u25B6 %s\n" % lines[0]
         for line in lines[1:-1]:
-            output += indent + u"\u2502 %s\n" % line
+            output += indent + "\u2502 %s\n" % line
         if len(lines) > 1:
-            output += indent + u"\u2514 %s\n" % lines[-1]
+            output += indent + "\u2514 %s\n" % lines[-1]
         return output
 
     def get_lines_for_unexpected_result(
@@ -174,13 +174,13 @@ class GroupingFormatter(base.BaseFormatter):
         test_name = test_name.encode("unicode-escape").decode("utf-8")
 
         if expected:
-            expected_text = u" [expected %s]" % expected
+            expected_text = " [expected %s]" % expected
         else:
-            expected_text = u""
+            expected_text = ""
 
-        lines = [u"%s%s %s" % (status, expected_text, test_name)]
+        lines = ["%s%s %s" % (status, expected_text, test_name)]
         if message:
-            lines.append(u"  \u2192 %s" % message)
+            lines.append("  \u2192 %s" % message)
         if stack:
             lines.append("")
             lines += [stackline for stackline in stack.splitlines()]
@@ -197,7 +197,7 @@ class GroupingFormatter(base.BaseFormatter):
                 known_intermittent,
             )
             lines += [
-                u"%s%s %s%s"
+                "%s%s %s%s"
                 % (
                     status,
                     expected,
@@ -222,7 +222,7 @@ class GroupingFormatter(base.BaseFormatter):
             )
 
         def make_subtests_failure(test_name, subtests, stack=None):
-            lines = [u"Unexpected subtest result in %s:" % test_name]
+            lines = ["Unexpected subtest result in %s:" % test_name]
             for subtest in subtests[:-1]:
                 add_subtest_failure(lines, subtest, None)
             add_subtest_failure(lines, subtests[-1], stack)
@@ -240,7 +240,7 @@ class GroupingFormatter(base.BaseFormatter):
             else:
                 failures_by_stack[failure["stack"]].append(failure)
 
-        for (stack, failures) in six.iteritems(failures_by_stack):
+        for stack, failures in six.iteritems(failures_by_stack):
             output += make_subtests_failure(test_name, failures, stack)
         return output
 
@@ -311,43 +311,43 @@ class GroupingFormatter(base.BaseFormatter):
         self.end_time = data["time"]
 
         if not self.interactive:
-            output = u"\n"
+            output = "\n"
         else:
             output = ""
 
-        output += u"Ran %i tests finished in %.1f seconds.\n" % (
+        output += "Ran %i tests finished in %.1f seconds.\n" % (
             self.completed_tests,
             (self.end_time - self.start_time) / 1000.0,
         )
-        output += u"  \u2022 %i ran as expected. %i tests skipped.\n" % (
+        output += "  \u2022 %i ran as expected. %i tests skipped.\n" % (
             sum(self.expected.values()),
             self.expected["SKIP"],
         )
         if self.known_intermittent_results:
-            output += u"  \u2022 %i known intermittent results.\n" % (
+            output += "  \u2022 %i known intermittent results.\n" % (
                 len(self.known_intermittent_results)
             )
 
         def text_for_unexpected_list(text, section):
             tests = self.unexpected_tests[section]
             if not tests:
-                return u""
-            return u"  \u2022 %i tests %s\n" % (len(tests), text)
+                return ""
+            return "  \u2022 %i tests %s\n" % (len(tests), text)
 
-        output += text_for_unexpected_list(u"crashed unexpectedly", "CRASH")
-        output += text_for_unexpected_list(u"had errors unexpectedly", "ERROR")
-        output += text_for_unexpected_list(u"failed unexpectedly", "FAIL")
+        output += text_for_unexpected_list("crashed unexpectedly", "CRASH")
+        output += text_for_unexpected_list("had errors unexpectedly", "ERROR")
+        output += text_for_unexpected_list("failed unexpectedly", "FAIL")
         output += text_for_unexpected_list(
-            u"precondition failed unexpectedly", "PRECONDITION_FAILED"
+            "precondition failed unexpectedly", "PRECONDITION_FAILED"
         )
-        output += text_for_unexpected_list(u"timed out unexpectedly", "TIMEOUT")
-        output += text_for_unexpected_list(u"passed unexpectedly", "PASS")
-        output += text_for_unexpected_list(u"unexpectedly okay", "OK")
+        output += text_for_unexpected_list("timed out unexpectedly", "TIMEOUT")
+        output += text_for_unexpected_list("passed unexpectedly", "PASS")
+        output += text_for_unexpected_list("unexpectedly okay", "OK")
 
         num_with_failing_subtests = len(self.tests_with_failing_subtests)
         if num_with_failing_subtests:
             output += (
-                u"  \u2022 %i tests had unexpected subtest results\n"
+                "  \u2022 %i tests had unexpected subtest results\n"
                 % num_with_failing_subtests
             )
         output += "\n"
@@ -355,13 +355,13 @@ class GroupingFormatter(base.BaseFormatter):
         # Repeat failing test output, so that it is easier to find, since the
         # non-interactive version prints all the test names.
         if not self.interactive and self.test_failure_text:
-            output += u"Tests with unexpected results:\n" + self.test_failure_text
+            output += "Tests with unexpected results:\n" + self.test_failure_text
 
         if self.known_intermittent_results:
             results = self.get_lines_for_known_intermittents(
                 self.known_intermittent_results
             )
-            output += u"Tests with known intermittent results:\n" + results
+            output += "Tests with known intermittent results:\n" + results
 
         return self.generate_output(text=output, new_display="")
 
diff --git a/testing/mozbase/mozlog/mozlog/formatters/html/html.py b/testing/mozbase/mozlog/mozlog/formatters/html/html.py
index c2cb0d5acc2c..d1b053e6a4f3 100755
--- a/testing/mozbase/mozlog/mozlog/formatters/html/html.py
+++ b/testing/mozbase/mozlog/mozlog/formatters/html/html.py
@@ -340,4 +340,4 @@ class HTMLFormatter(base.BaseFormatter):
                 ),
             )
 
-        return u"<!DOCTYPE html>\n" + doc.unicode(indent=2)
+        return "<!DOCTYPE html>\n" + doc.unicode(indent=2)
diff --git a/testing/mozbase/mozlog/mozlog/formatters/html/xmlgen.py b/testing/mozbase/mozlog/mozlog/formatters/html/xmlgen.py
index 933958b9f1b2..eda2d8d36a29 100644
--- a/testing/mozbase/mozlog/mozlog/formatters/html/xmlgen.py
+++ b/testing/mozbase/mozlog/mozlog/formatters/html/xmlgen.py
@@ -35,7 +35,6 @@ if sys.version_info >= (3, 0):
             return x.__unicode__()
         return str(x)
 
-
 else:
 
     def u(s):
@@ -255,7 +254,6 @@ class SimpleUnicodeVisitor(object):
 
 
 class HtmlVisitor(SimpleUnicodeVisitor):
-
     single = dict(
         [
             (x, 1)
diff --git a/testing/mozbase/mozlog/mozlog/formatters/process.py b/testing/mozbase/mozlog/mozlog/formatters/process.py
index 4b978acf56d0..012c7a080383 100644
--- a/testing/mozbase/mozlog/mozlog/formatters/process.py
+++ b/testing/mozbase/mozlog/mozlog/formatters/process.py
@@ -27,7 +27,6 @@ def strsig(n):
                 and k != "SIGCLD"
                 and k != "SIGPOLL"
             ):
-
                 _SIG_NAME[getattr(signal, k)] = k
 
         # Realtime signals mostly have no names
@@ -52,7 +51,7 @@ def strstatus(status):
     if os.name != "posix":
         # Windows error codes are easier to look up if printed in hexadecimal
         if status < 0:
-            status += 2 ** 32
+            status += 2**32
         return "exit %x" % status
     elif status >= 0:
         return "exit %d" % status
diff --git a/testing/mozbase/mozlog/mozlog/handlers/base.py b/testing/mozbase/mozlog/mozlog/handlers/base.py
index 59fc05cc1f89..064b1dee0b96 100644
--- a/testing/mozbase/mozlog/mozlog/handlers/base.py
+++ b/testing/mozbase/mozlog/mozlog/handlers/base.py
@@ -111,7 +111,7 @@ class StreamHandler(BaseHandler):
                 # consequences for the executed tests, anyways).
                 try:
                     self.stream.write(formatted)
-                except (UnicodeEncodeError):
+                except UnicodeEncodeError:
                     return
             else:
                 if isinstance(formatted, six.text_type):
diff --git a/testing/mozbase/mozlog/mozlog/handlers/valgrindhandler.py b/testing/mozbase/mozlog/mozlog/handlers/valgrindhandler.py
index 49bb4b5b9eaa..0f9b06e8f79b 100644
--- a/testing/mozbase/mozlog/mozlog/handlers/valgrindhandler.py
+++ b/testing/mozbase/mozlog/mozlog/handlers/valgrindhandler.py
@@ -120,14 +120,14 @@ class ValgrindFilter(object):
                 # fields from the incoming message, since there's nowhere
                 # else to get them from.
                 output_message = {  # Mandatory fields
-                    u"action": "valgrind_error",
-                    u"time": msg["time"],
-                    u"thread": msg["thread"],
-                    u"pid": msg["pid"],
-                    u"source": msg["source"],
+                    "action": "valgrind_error",
+                    "time": msg["time"],
+                    "thread": msg["thread"],
+                    "pid": msg["pid"],
+                    "source": msg["source"],
                     # valgrind_error specific fields
-                    u"primary": self.curr_failure_msg,
-                    u"secondary": self.buffered_lines,
+                    "primary": self.curr_failure_msg,
+                    "secondary": self.buffered_lines,
                 }
                 self.curr_failure_msg = ""
                 self.buffered_lines = []
diff --git a/testing/mozbase/mozlog/tests/test_capture.py b/testing/mozbase/mozlog/tests/test_capture.py
index 4adbda41801d..6e14e155aa03 100644
--- a/testing/mozbase/mozlog/tests/test_capture.py
+++ b/testing/mozbase/mozlog/tests/test_capture.py
@@ -30,7 +30,7 @@ class TestCaptureIO(unittest.TestCase):
         self.assertIn("STDOUT: message 1", messages)
         self.assertIn("STDOUT: message 2", messages)
         self.assertIn("STDERR: message 3", messages)
-        self.assertIn(u"STDOUT: \xff", messages)
+        self.assertIn("STDOUT: \xff", messages)
 
 
 if __name__ == "__main__":
diff --git a/testing/mozbase/mozlog/tests/test_structured.py b/testing/mozbase/mozlog/tests/test_structured.py
index 833e856761ca..e8816fc7e9a4 100644
--- a/testing/mozbase/mozlog/tests/test_structured.py
+++ b/testing/mozbase/mozlog/tests/test_structured.py
@@ -660,7 +660,7 @@ class TestTypeConversions(BaseStructuredTest):
                     b"\xf0\x90\x8d\x84\xf0\x90\x8c\xb4\xf0\x90"
                     b"\x8d\x83\xf0\x90\x8d\x84".decode(),
                     42,
-                    u"\u16a4",
+                    "\u16a4",
                 )
             )
         else:
@@ -669,13 +669,13 @@ class TestTypeConversions(BaseStructuredTest):
                     "\xf0\x90\x8d\x84\xf0\x90\x8c\xb4\xf0\x90"
                     "\x8d\x83\xf0\x90\x8d\x84",
                     42,
-                    u"\u16a4",
+                    "\u16a4",
                 )
             )
         self.assert_log_equals(
             {
                 "action": "test_start",
-                "test": (u"\U00010344\U00010334\U00010343\U00010344", u"42", u"\u16a4"),
+                "test": ("\U00010344\U00010334\U00010343\U00010344", "42", "\u16a4"),
             }
         )
         self.logger.suite_end()
@@ -899,7 +899,7 @@ class TestCommandline(unittest.TestCase):
     def test_setup_logging_optparse_unicode(self):
         parser = optparse.OptionParser()
         commandline.add_logging_group(parser)
-        args, _ = parser.parse_args([u"--log-raw=-"])
+        args, _ = parser.parse_args(["--log-raw=-"])
         logger = commandline.setup_logging("test_optparse_unicode", args, {})
         self.assertEqual(len(logger.handlers), 1)
         self.assertEqual(logger.handlers[0].stream, sys.stdout)
diff --git a/testing/mozbase/mozpower/tests/test_mozpower.py b/testing/mozbase/mozpower/tests/test_mozpower.py
index fd513e836bb6..1ad6194c0ad3 100644
--- a/testing/mozbase/mozpower/tests/test_mozpower.py
+++ b/testing/mozbase/mozpower/tests/test_mozpower.py
@@ -55,7 +55,6 @@ def test_mozpower_processor_info_missing_error():
 
     # Test failures in macos processor information parsing
     with mock.patch.object(MozPower, "_get_os", return_value="Darwin") as _:
-
         with mock.patch("os.path.exists") as os_mock:
             os_mock.side_effect = os_side_effect_false
 
@@ -74,7 +73,6 @@ def test_mozpower_processor_info_missing_error():
 
     # Test failures in linux processor information parsing
     with mock.patch.object(MozPower, "_get_os", return_value="Linux") as _:
-
         with mock.patch("os.path.exists") as os_mock:
             os_mock.side_effect = os_side_effect_false
 
diff --git a/testing/mozbase/mozprocess/mozprocess/processhandler.py b/testing/mozbase/mozprocess/mozprocess/processhandler.py
index 2e106456a25b..58e0a819326e 100644
--- a/testing/mozbase/mozprocess/mozprocess/processhandler.py
+++ b/testing/mozbase/mozprocess/mozprocess/processhandler.py
@@ -116,7 +116,6 @@ class ProcessHandlerMixin(object):
             ignore_children=False,
             encoding="utf-8",
         ):
-
             # Parameter for whether or not we should attempt to track child processes
             self._ignore_children = ignore_children
             self._job = None
diff --git a/testing/mozbase/mozprofile/mozprofile/cli.py b/testing/mozbase/mozprofile/mozprofile/cli.py
index 7addb1165d35..104f6bd08c79 100755
--- a/testing/mozbase/mozprofile/mozprofile/cli.py
+++ b/testing/mozbase/mozprofile/mozprofile/cli.py
@@ -90,7 +90,6 @@ class MozProfileCLI(object):
         (self.options, self.args) = self.parser.parse_args(args)
 
     def add_options(self, parser):
-
         parser.add_option(
             "-p",
             "--profile",
diff --git a/testing/mozbase/mozprofile/mozprofile/diff.py b/testing/mozbase/mozprofile/mozprofile/diff.py
index f8376e4d7b14..192b59cd9ee2 100644
--- a/testing/mozbase/mozprofile/mozprofile/diff.py
+++ b/testing/mozbase/mozprofile/mozprofile/diff.py
@@ -18,7 +18,6 @@ __all__ = ["diff", "diff_profiles"]
 
 
 def diff(profile1, profile2, diff_function=difflib.unified_diff):
-
     profiles = (profile1, profile2)
     parts = {}
     parts_dict = {}
@@ -59,7 +58,6 @@ def diff(profile1, profile2, diff_function=difflib.unified_diff):
 
 
 def diff_profiles(args=sys.argv[1:]):
-
     # parse command line
     usage = "%prog [options] profile1 profile2"
     parser = optparse.OptionParser(usage=usage, description=__doc__)
diff --git a/testing/mozbase/mozprofile/mozprofile/profile.py b/testing/mozbase/mozprofile/mozprofile/profile.py
index 401715c93d8a..25e10d23bfef 100644
--- a/testing/mozbase/mozprofile/mozprofile/profile.py
+++ b/testing/mozbase/mozprofile/mozprofile/profile.py
@@ -410,7 +410,6 @@ class Profile(BaseProfile):
         for prefs_file in ("user.js", "prefs.js"):
             path = os.path.join(self.profile, prefs_file)
             if os.path.exists(path):
-
                 # prefs that get their own section
                 # This is currently only 'network.proxy.autoconfig_url'
                 # but could be expanded to include others
diff --git a/testing/mozbase/mozprofile/mozprofile/view.py b/testing/mozbase/mozprofile/mozprofile/view.py
index 93566232324c..455751148b25 100644
--- a/testing/mozbase/mozprofile/mozprofile/view.py
+++ b/testing/mozbase/mozprofile/mozprofile/view.py
@@ -17,7 +17,6 @@ __all__ = ["view_profile"]
 
 
 def view_profile(args=sys.argv[1:]):
-
     usage = "%prog [options] profile_path <...>"
     parser = optparse.OptionParser(usage=usage, description=__doc__)
     options, args = parser.parse_args(args)
diff --git a/testing/mozbase/mozproxy/mozproxy/backends/mitm/desktop.py b/testing/mozbase/mozproxy/mozproxy/backends/mitm/desktop.py
index f9c30c9b0ecb..916477b0948a 100644
--- a/testing/mozbase/mozproxy/mozproxy/backends/mitm/desktop.py
+++ b/testing/mozbase/mozproxy/mozproxy/backends/mitm/desktop.py
@@ -137,7 +137,6 @@ class MitmproxyDesktop(Mitmproxy):
             ) in contents:
                 LOG.info("Verified mitmproxy CA certificate is installed in Firefox")
             else:
-
                 return False
         except Exception as e:
             LOG.info("failed to read Firefox policies file, exeption: %s" % e)
diff --git a/testing/mozbase/mozproxy/mozproxy/backends/mitm/mitm.py b/testing/mozbase/mozproxy/mozproxy/backends/mitm/mitm.py
index e7689d27a65f..5ef19282df7b 100644
--- a/testing/mozbase/mozproxy/mozproxy/backends/mitm/mitm.py
+++ b/testing/mozbase/mozproxy/mozproxy/backends/mitm/mitm.py
@@ -178,7 +178,6 @@ class Mitmproxy(Playback):
             raise Exception("playback_files should be a list")
 
         for playback_file in self.config["playback_files"]:
-
             if playback_file.startswith("https://") and "mozilla.com" in playback_file:
                 # URL provided
                 dest = os.path.join(self.mozproxy_dir, os.path.basename(playback_file))
@@ -271,7 +270,6 @@ class Mitmproxy(Playback):
 
         # record mode
         if self.record_mode:
-
             # generate recording script paths
 
             command.extend(
diff --git a/testing/mozbase/mozproxy/mozproxy/backends/mitm/scripts/inject-deterministic.py b/testing/mozbase/mozproxy/mozproxy/backends/mitm/scripts/inject-deterministic.py
index 70536d76e684..7134643d6a90 100644
--- a/testing/mozbase/mozproxy/mozproxy/backends/mitm/scripts/inject-deterministic.py
+++ b/testing/mozbase/mozproxy/mozproxy/backends/mitm/scripts/inject-deterministic.py
@@ -128,7 +128,6 @@ class AddDeterministic:
                 with open(
                     path.join(path.dirname(__file__), "catapult/deterministic.js"), "r"
                 ) as jsfile:
-
                     js = jsfile.read().replace(
                         "REPLACE_LOAD_TIMESTAMP", str(self.millis)
                     )
diff --git a/testing/mozbase/mozrunner/mozrunner/devices/android_device.py b/testing/mozbase/mozrunner/mozrunner/devices/android_device.py
index 6016425c8a15..45565349f513 100644
--- a/testing/mozbase/mozrunner/mozrunner/devices/android_device.py
+++ b/testing/mozbase/mozrunner/mozrunner/devices/android_device.py
@@ -176,7 +176,6 @@ AVD_DICT = {
 
 
 def _get_device(substs, device_serial=None):
-
     adb_path = _find_sdk_exe(substs, "adb", False)
     if not adb_path:
         adb_path = "adb"
diff --git a/testing/mozbase/mozrunner/mozrunner/devices/base.py b/testing/mozbase/mozrunner/mozrunner/devices/base.py
index d1fa66005274..88db2065d80f 100644
--- a/testing/mozbase/mozrunner/mozrunner/devices/base.py
+++ b/testing/mozbase/mozrunner/mozrunner/devices/base.py
@@ -242,12 +242,12 @@ class ProfileConfigParser(RawConfigParser):
     def write(self, fp):
         if self._defaults:
             fp.write("[%s]\n" % ConfigParser.DEFAULTSECT)
-            for (key, value) in self._defaults.items():
+            for key, value in self._defaults.items():
                 fp.write("%s=%s\n" % (key, str(value).replace("\n", "\n\t")))
             fp.write("\n")
         for section in self._sections:
             fp.write("[%s]\n" % section)
-            for (key, value) in self._sections[section].items():
+            for key, value in self._sections[section].items():
                 if key == "__name__":
                     continue
                 if (value is not None) or (self._optcre == self.OPTCRE):
diff --git a/testing/mozbase/mozrunner/mozrunner/utils.py b/testing/mozbase/mozrunner/mozrunner/utils.py
index 5bfaede7313e..46c20c1997b3 100755
--- a/testing/mozbase/mozrunner/mozrunner/utils.py
+++ b/testing/mozbase/mozrunner/mozrunner/utils.py
@@ -47,7 +47,6 @@ try:
             ret["Dependencies"] = "\n" + dist.get_metadata("requires.txt")
         return ret
 
-
 except ImportError:
     # package resources not avaialable
     def get_metadata_from_egg(module):
diff --git a/testing/mozbase/mozsystemmonitor/mozsystemmonitor/resourcemonitor.py b/testing/mozbase/mozsystemmonitor/mozsystemmonitor/resourcemonitor.py
index 847d3e8d3da5..824863cbb604 100644
--- a/testing/mozbase/mozsystemmonitor/mozsystemmonitor/resourcemonitor.py
+++ b/testing/mozbase/mozsystemmonitor/mozsystemmonitor/resourcemonitor.py
@@ -118,7 +118,6 @@ def _collect(pipe, poll_interval):
     data = []
 
     try:
-
         # Establish initial values.
 
         # We should ideally use a monotonic clock. However, Python 2.7 doesn't
@@ -178,7 +177,6 @@ def _collect(pipe, poll_interval):
         warnings.warn("_collect failed: %s" % e)
 
     finally:
-
         for entry in data:
             pipe.send(entry)
 
diff --git a/testing/mozbase/moztest/moztest/adapters/unit.py b/testing/mozbase/moztest/moztest/adapters/unit.py
index 72c2f3005218..4273adf35322 100644
--- a/testing/mozbase/moztest/moztest/adapters/unit.py
+++ b/testing/mozbase/moztest/moztest/adapters/unit.py
@@ -169,7 +169,6 @@ class StructuredTestResult(TextTestResult):
 
 
 class StructuredTestRunner(unittest.TextTestRunner):
-
     resultclass = StructuredTestResult
 
     def __init__(self, **kwargs):
diff --git a/testing/mozbase/mozversion/mozversion/mozversion.py b/testing/mozbase/mozversion/mozversion/mozversion.py
index bea53e0a6d7a..9a93bf4e20b5 100644
--- a/testing/mozbase/mozversion/mozversion/mozversion.py
+++ b/testing/mozbase/mozversion/mozversion/mozversion.py
@@ -126,7 +126,7 @@ def get_version(binary=None):
     else:
         version = LocalVersion(binary)
 
-    for (key, value) in sorted(version._info.items()):
+    for key, value in sorted(version._info.items()):
         if value:
             version._logger.info("%s: %s" % (key, value))
 
diff --git a/testing/mozbase/setup_development.py b/testing/mozbase/setup_development.py
index af065922d363..73aba7aaee8d 100755
--- a/testing/mozbase/setup_development.py
+++ b/testing/mozbase/setup_development.py
@@ -145,7 +145,6 @@ def unroll_dependencies(dependencies):
         packages.update(deps)
 
     while len(order) != len(packages):
-
         for package in packages.difference(order):
             if set(dependencies.get(package, set())).issubset(order):
                 order.append(package)
@@ -159,7 +158,6 @@ def unroll_dependencies(dependencies):
 
 
 def main(args=sys.argv[1:]):
-
     # parse command line options
     usage = "%prog [options] [package] [package] [...]"
     parser = OptionParser(usage=usage, description=__doc__)
diff --git a/testing/mozharness/examples/venv.py b/testing/mozharness/examples/venv.py
index 82ee3d0109ce..ee16162ceae4 100755
--- a/testing/mozharness/examples/venv.py
+++ b/testing/mozharness/examples/venv.py
@@ -17,6 +17,7 @@ from mozharness.base.errors import PythonErrorList
 from mozharness.base.python import virtualenv_config_options, VirtualenvMixin
 from mozharness.base.script import BaseScript
 
+
 # VirtualenvExample {{{1
 class VirtualenvExample(VirtualenvMixin, BaseScript):
     config_options = [
diff --git a/testing/mozharness/external_tools/mouse_and_screen_resolution.py b/testing/mozharness/external_tools/mouse_and_screen_resolution.py
index ad1f8d9e4b8e..db78c1c32166 100755
--- a/testing/mozharness/external_tools/mouse_and_screen_resolution.py
+++ b/testing/mozharness/external_tools/mouse_and_screen_resolution.py
@@ -51,7 +51,6 @@ def wfetch(url, retries=5):
 
 
 def main():
-
     # NOTE: this script was written for windows 7, but works well with windows 10
     parser = OptionParser()
     parser.add_option(
diff --git a/testing/mozharness/mozharness/base/config.py b/testing/mozharness/mozharness/base/config.py
index d12b3aecad96..d97bcb6a933b 100644
--- a/testing/mozharness/mozharness/base/config.py
+++ b/testing/mozharness/mozharness/base/config.py
@@ -100,7 +100,7 @@ class ReadOnlyDict(dict):
         assert not self._lock, "ReadOnlyDict is locked!"
 
     def lock(self):
-        for (k, v) in list(self.items()):
+        for k, v in list(self.items()):
             self[k] = make_immutable(v)
         self._lock = True
 
diff --git a/testing/mozharness/mozharness/base/python.py b/testing/mozharness/mozharness/base/python.py
index 1d20786681b2..2f281e7766f2 100644
--- a/testing/mozharness/mozharness/base/python.py
+++ b/testing/mozharness/mozharness/base/python.py
@@ -508,7 +508,6 @@ class VirtualenvMixin(object):
                     )
 
                     if debug_exe_dir.exists():
-
                         for executable in {
                             "python.exe",
                             "python_d.exe",
diff --git a/testing/mozharness/mozharness/base/script.py b/testing/mozharness/mozharness/base/script.py
index 978ac8616d53..e2272036b02b 100644
--- a/testing/mozharness/mozharness/base/script.py
+++ b/testing/mozharness/mozharness/base/script.py
@@ -201,7 +201,7 @@ class PlatformMixin(object):
         if self._is_darwin():
             # osx is a special snowflake and to ensure the arch, it is better to use the following
             return (
-                sys.maxsize > 2 ** 32
+                sys.maxsize > 2**32
             )  # context: https://docs.python.org/2/library/platform.html
         else:
             # Using machine() gives you the architecture of the host rather
@@ -578,7 +578,7 @@ class ScriptMixin(PlatformMixin):
             else:
                 local_file = open(file_name, "wb")
             while True:
-                block = f.read(1024 ** 2)
+                block = f.read(1024**2)
                 if not block:
                     if f_length is not None and got_length != f_length:
                         raise URLError(
diff --git a/testing/mozharness/mozharness/mozilla/testing/android.py b/testing/mozharness/mozharness/mozilla/testing/android.py
index 7e1770755284..37a57747caee 100644
--- a/testing/mozharness/mozharness/mozilla/testing/android.py
+++ b/testing/mozharness/mozharness/mozilla/testing/android.py
@@ -291,7 +291,6 @@ class AndroidMixin(object):
         dir = self.query_abs_dirs()["abs_blob_upload_dir"]
         perf_path = os.path.join(dir, "android-performance.log")
         with open(perf_path, "w") as f:
-
             f.write("\n\nHost cpufreq/scaling_governor:\n")
             cpus = glob.glob("/sys/devices/system/cpu/cpu*/cpufreq/scaling_governor")
             for cpu in cpus:
@@ -473,7 +472,7 @@ class AndroidMixin(object):
             return self.device.shell_output(
                 cmd, timeout=30, enable_run_as=enable_run_as
             )
-        except (mozdevice.ADBTimeoutError) as e:
+        except mozdevice.ADBTimeoutError as e:
             self.info(
                 "Failed to run shell command %s from %s: %s %s"
                 % (cmd, self.device_name, type(e).__name__, e)
diff --git a/testing/mozharness/mozharness/mozilla/testing/per_test_base.py b/testing/mozharness/mozharness/mozilla/testing/per_test_base.py
index f93a9a09d709..fb5eda2b9132 100644
--- a/testing/mozharness/mozharness/mozilla/testing/per_test_base.py
+++ b/testing/mozharness/mozharness/mozilla/testing/per_test_base.py
@@ -71,7 +71,7 @@ class SingleTestMixin(object):
         #  HACK: import here so we don't need import for rest of class
         from manifestparser import TestManifest
 
-        for (path, suite) in manifests:
+        for path, suite in manifests:
             if os.path.exists(path):
                 man = TestManifest([path], strict=False)
                 active = man.active_tests(
@@ -122,7 +122,7 @@ class SingleTestMixin(object):
         import manifest
 
         self.reftest_test_dir = os.path.join(dirs["abs_reftest_dir"], "tests")
-        for (path, suite, subsuite) in ref_manifests:
+        for path, suite, subsuite in ref_manifests:
             if os.path.exists(path):
                 man = manifest.ReftestManifest()
                 man.load(path)
@@ -282,7 +282,7 @@ class SingleTestMixin(object):
 
             repo_tests_path = os.path.join("testing", "web-platform", extra, "tests")
             tests_path = os.path.join("tests", "web-platform", extra, "tests")
-            for (type, path, test) in man:
+            for type, path, test in man:
                 if type not in ["testharness", "reftest", "wdspec"]:
                     continue
                 repo_path = os.path.join(repo_tests_path, path)
diff --git a/testing/mozharness/mozharness/mozilla/testing/testbase.py b/testing/mozharness/mozharness/mozilla/testing/testbase.py
index e8f37ceb8bee..1519ff112c2a 100755
--- a/testing/mozharness/mozharness/mozilla/testing/testbase.py
+++ b/testing/mozharness/mozharness/mozilla/testing/testbase.py
@@ -301,6 +301,7 @@ class TestingMixin(
         This function helps dealing with downloading files while outside
         of the releng network.
         """
+
         # Code based on http://code.activestate.com/recipes/305288-http-basic-authentication
         def _urlopen_basic_auth(url, **kwargs):
             self.info("We want to download this file %s" % url)
diff --git a/testing/mozharness/scripts/android_emulator_unittest.py b/testing/mozharness/scripts/android_emulator_unittest.py
index 47cf13dde3e5..9f51f2ad4435 100644
--- a/testing/mozharness/scripts/android_emulator_unittest.py
+++ b/testing/mozharness/scripts/android_emulator_unittest.py
@@ -399,7 +399,7 @@ class AndroidEmulatorTest(
             ("xpcshell", {"xpcshell": "xpcshell"}),
         ]
         suites = []
-        for (category, all_suites) in all:
+        for category, all_suites in all:
             cat_suites = self.query_per_test_category_suites(category, all_suites)
             for k in cat_suites.keys():
                 suites.append((k, cat_suites[k]))
@@ -472,7 +472,7 @@ class AndroidEmulatorTest(
         per_test_args = []
         suites = self._query_suites()
         minidump = self.query_minidump_stackwalk()
-        for (per_test_suite, suite) in suites:
+        for per_test_suite, suite in suites:
             self.test_suite = suite
 
             try:
diff --git a/testing/mozharness/scripts/android_hardware_unittest.py b/testing/mozharness/scripts/android_hardware_unittest.py
index 065d74557bc0..3abd79f0e24d 100644
--- a/testing/mozharness/scripts/android_hardware_unittest.py
+++ b/testing/mozharness/scripts/android_hardware_unittest.py
@@ -327,7 +327,7 @@ class AndroidHardwareTest(
             ("xpcshell", {"xpcshell": "xpcshell"}),
         ]
         suites = []
-        for (category, all_suites) in all:
+        for category, all_suites in all:
             cat_suites = self.query_per_test_category_suites(category, all_suites)
             for k in cat_suites.keys():
                 suites.append((k, cat_suites[k]))
@@ -401,7 +401,7 @@ class AndroidHardwareTest(
         per_test_args = []
         suites = self._query_suites()
         minidump = self.query_minidump_stackwalk()
-        for (per_test_suite, suite) in suites:
+        for per_test_suite, suite in suites:
             self.test_suite = suite
 
             try:
diff --git a/testing/mozharness/scripts/awsy_script.py b/testing/mozharness/scripts/awsy_script.py
index 9071dab75d78..e54a342ca65a 100644
--- a/testing/mozharness/scripts/awsy_script.py
+++ b/testing/mozharness/scripts/awsy_script.py
@@ -93,7 +93,6 @@ class AWSY(TestingMixin, MercurialScript, TooltoolMixin, CodeCoverageMixin):
     ]
 
     def __init__(self, **kwargs):
-
         kwargs.setdefault("config_options", self.config_options)
         kwargs.setdefault(
             "all_actions",
diff --git a/testing/mozharness/scripts/does_it_crash.py b/testing/mozharness/scripts/does_it_crash.py
index ad81e87e2a18..6a9ffe3e355b 100755
--- a/testing/mozharness/scripts/does_it_crash.py
+++ b/testing/mozharness/scripts/does_it_crash.py
@@ -120,7 +120,6 @@ class DoesItCrash(BaseScript):
             self.error("unable to terminate process!")
 
     def run_thing(self):
-
         self.timed_out = False
 
         def timeout_handler(proc):
diff --git a/testing/mozharness/scripts/openh264_build.py b/testing/mozharness/scripts/openh264_build.py
index 1c6089e3f193..a0965af0af98 100755
--- a/testing/mozharness/scripts/openh264_build.py
+++ b/testing/mozharness/scripts/openh264_build.py
@@ -103,7 +103,6 @@ class OpenH264Build(TransferMixin, VCSScript, TooltoolMixin):
         all_actions=all_actions,
         default_actions=default_actions,
     ):
-
         # Default configuration
         default_config = {
             "debug_build": False,
diff --git a/testing/mozharness/test/test_base_script.py b/testing/mozharness/test/test_base_script.py
index 8acb63005362..d61cc5f57603 100644
--- a/testing/mozharness/test/test_base_script.py
+++ b/testing/mozharness/test/test_base_script.py
@@ -483,13 +483,13 @@ class TestHelperFunctions(unittest.TestCase):
         self.s = script.BaseScript(initial_config_file="test/test.json")
         # create a very long path that the command-prompt cannot delete
         # by using unicode format (max path length 32000)
-        path = u"\\\\?\\%s\\test_dir" % os.getcwd()
-        win32file.CreateDirectoryExW(u".", path)
+        path = "\\\\?\\%s\\test_dir" % os.getcwd()
+        win32file.CreateDirectoryExW(".", path)
 
         for x in range(0, 20):
             print("path=%s" % path)
-            path = path + u"\\%sxxxxxxxxxxxxxxxxxxxx" % x
-            win32file.CreateDirectoryExW(u".", path)
+            path = path + "\\%sxxxxxxxxxxxxxxxxxxxx" % x
+            win32file.CreateDirectoryExW(".", path)
         self.s.rmtree("test_dir")
         self.assertFalse(os.path.exists("test_dir"), msg="rmtree unsuccessful")
 
diff --git a/testing/performance/hooks_recording.py b/testing/performance/hooks_recording.py
index 63cc65caa0ea..bfa61469d132 100644
--- a/testing/performance/hooks_recording.py
+++ b/testing/performance/hooks_recording.py
@@ -24,7 +24,6 @@ SCM_1_LOGIN_SITES = ("facebook", "netflix")
 
 
 def before_iterations(kw):
-
     global next_site
     print("Setting up next site to record.")
 
diff --git a/testing/raptor/raptor/browsertime/base.py b/testing/raptor/raptor/browsertime/base.py
index 1da49f1a31f6..addb357c2be1 100644
--- a/testing/raptor/raptor/browsertime/base.py
+++ b/testing/raptor/raptor/browsertime/base.py
@@ -8,7 +8,6 @@ import json
 import os
 import pathlib
 import re
-import signal
 import sys
 from abc import ABCMeta, abstractmethod
 from copy import deepcopy
@@ -39,11 +38,12 @@ class Browsertime(Perftest):
     def browsertime_args(self):
         pass
 
-    def __init__(self, app, binary, **kwargs):
+    def __init__(self, app, binary, process_handler=None, **kwargs):
         self.browsertime = True
         self.browsertime_failure = ""
         self.browsertime_user_args = []
 
+        self.process_handler = process_handler or mozprocess.ProcessHandler
         for key in list(kwargs):
             if key.startswith("browsertime_"):
                 value = kwargs.pop(key)
@@ -765,27 +765,9 @@ class Browsertime(Perftest):
 
         return True
 
-    def kill(self, proc):
-        if "win" in self.config["platform"]:
-            proc.send_signal(signal.CTRL_BREAK_EVENT)
-        else:
-            os.killpg(proc.pid, signal.SIGKILL)
-        proc.wait()
-
     def run_extra_profiler_run(
         self, test, timeout, proc_timeout, output_timeout, line_handler, env
     ):
-        self.timed_out = False
-        self.output_timed_out = False
-
-        def timeout_handler(proc):
-            self.timed_out = True
-            self.kill(proc)
-
-        def output_timeout_handler(proc):
-            self.output_timed_out = True
-            self.kill(proc)
-
         try:
             LOG.info(
                 "Running browsertime with the profiler enabled after the main run."
@@ -795,25 +777,18 @@ class Browsertime(Perftest):
             LOG.info(
                 "browsertime profiling cmd: {}".format(" ".join([str(c) for c in cmd]))
             )
-            mozprocess.run_and_wait(
-                cmd,
-                output_line_handler=line_handler,
-                env=env,
-                timeout=proc_timeout,
-                timeout_handler=timeout_handler,
-                output_timeout=output_timeout,
-                output_timeout_handler=output_timeout_handler,
-                text=False,
-            )
+            proc = self.process_handler(cmd, processOutputLine=line_handler, env=env)
+            proc.run(timeout=proc_timeout, outputTimeout=output_timeout)
+            proc.wait()
 
             # Do not raise exception for the browsertime failure or timeout for this case.
             # Second profiler browsertime run is fallible.
-            if self.output_timed_out:
+            if proc.outputTimedOut:
                 LOG.info(
                     "Browsertime process for extra profiler run timed out after "
                     f"waiting {output_timeout} seconds for output"
                 )
-            if self.timed_out:
+            if proc.timedOut:
                 LOG.info(
                     "Browsertime process for extra profiler run timed out after "
                     f"{proc_timeout} seconds"
@@ -828,17 +803,6 @@ class Browsertime(Perftest):
             LOG.info("Failed during the extra profiler run: " + str(e))
 
     def run_test(self, test, timeout):
-        self.timed_out = False
-        self.output_timed_out = False
-
-        def timeout_handler(proc):
-            self.timed_out = True
-            self.kill(proc)
-
-        def output_timeout_handler(proc):
-            self.output_timed_out = True
-            self.kill(proc)
-
         self.run_test_setup(test)
         # timeout is a single page-load timeout value (ms) from the test INI
         # this will be used for btime --timeouts.pageLoad
@@ -873,6 +837,9 @@ class Browsertime(Perftest):
             ffmpeg_dir = os.path.dirname(os.path.abspath(self.browsertime_ffmpeg))
             old_path = env.setdefault("PATH", "")
             new_path = os.pathsep.join([ffmpeg_dir, old_path])
+            if isinstance(new_path, six.text_type):
+                # Python 2 doesn't like unicode in the environment.
+                new_path = new_path.encode("utf-8", "strict")
             env["PATH"] = new_path
 
         LOG.info("PATH: {}".format(env["PATH"]))
@@ -881,7 +848,7 @@ class Browsertime(Perftest):
             line_matcher = re.compile(r".*(\[.*\])\s+([a-zA-Z]+):\s+(.*)")
 
             def _create_line_handler(extra_profiler_run=False):
-                def _line_handler(proc, line):
+                def _line_handler(line):
                     """This function acts as a bridge between browsertime
                     and raptor. It reforms the lines to get rid of information
                     that is not needed, and outputs them appropriately based
@@ -951,23 +918,18 @@ class Browsertime(Perftest):
                 f"and output_timeout={output_timeout}"
             )
 
-            mozprocess.run_and_wait(
-                cmd,
-                output_line_handler=_create_line_handler(),
-                env=env,
-                timeout=proc_timeout,
-                timeout_handler=timeout_handler,
-                output_timeout=output_timeout,
-                output_timeout_handler=output_timeout_handler,
-                text=False,
+            proc = self.process_handler(
+                cmd, processOutputLine=_create_line_handler(), env=env
             )
+            proc.run(timeout=proc_timeout, outputTimeout=output_timeout)
+            proc.wait()
 
-            if self.output_timed_out:
+            if proc.outputTimedOut:
                 raise Exception(
                     f"Browsertime process timed out after waiting {output_timeout} seconds "
                     "for output"
                 )
-            if self.timed_out:
+            if proc.timedOut:
                 raise Exception(
                     f"Browsertime process timed out after {proc_timeout} seconds"
                 )
diff --git a/testing/raptor/raptor/filters.py b/testing/raptor/raptor/filters.py
index f779430d4d52..87b0d827e603 100644
--- a/testing/raptor/raptor/filters.py
+++ b/testing/raptor/raptor/filters.py
@@ -64,7 +64,6 @@ def register_filter(func):
 
 
 def filters(*args):
-
     filters_ = [_FILTERS[filter] for filter in args]
     return filters_
 
diff --git a/testing/raptor/raptor/output.py b/testing/raptor/raptor/output.py
index 260167a7ca27..4ee7ebec3056 100644
--- a/testing/raptor/raptor/output.py
+++ b/testing/raptor/raptor/output.py
@@ -114,7 +114,6 @@ class PerftestOutput(object):
         support_data_by_type = {}
 
         for data_set in self.supporting_data:
-
             data_type = data_set["type"]
             LOG.info("summarizing %s data" % data_type)
 
@@ -1353,7 +1352,6 @@ class RaptorOutput(PerftestOutput):
                     subtests.append(new_subtest)
 
             elif test["type"] == "benchmark":
-
                 if any(
                     [
                         "youtube-playback" in measurement
diff --git a/testing/raptor/raptor/perftest.py b/testing/raptor/raptor/perftest.py
index c1a9bb94d814..939b32ddb6ad 100644
--- a/testing/raptor/raptor/perftest.py
+++ b/testing/raptor/raptor/perftest.py
@@ -505,7 +505,6 @@ class Perftest(object):
         # run is added with extra_profiler_run flag.
         if self.config["gecko_profile"] or self.config.get("extra_profiler_run"):
             if self.config["app"] == "firefox":
-
                 self.gecko_profiler.symbolicate()
                 # clean up the temp gecko profiling folders
                 LOG.info("cleaning up after gecko profiling")
diff --git a/testing/talos/INSTALL.py b/testing/talos/INSTALL.py
index 73edfbb7b5e4..6bdbfa13fa7f 100755
--- a/testing/talos/INSTALL.py
+++ b/testing/talos/INSTALL.py
@@ -36,7 +36,6 @@ def which(binary, path=os.environ["PATH"]):
 
 
 def main(args=sys.argv[1:]):
-
     # sanity check
     # ensure setup.py exists
     setup_py = os.path.join(here, "setup.py")
diff --git a/testing/talos/talos/cmanager_base.py b/testing/talos/talos/cmanager_base.py
index 2a91c8c48f2d..54c0c1bda9d8 100644
--- a/testing/talos/talos/cmanager_base.py
+++ b/testing/talos/talos/cmanager_base.py
@@ -4,7 +4,6 @@
 
 
 class CounterManager(object):
-
     counterDict = {}
 
     def __init__(self):
diff --git a/testing/talos/talos/cmanager_linux.py b/testing/talos/talos/cmanager_linux.py
index c0741b2c6a12..81f220aaba2b 100644
--- a/testing/talos/talos/cmanager_linux.py
+++ b/testing/talos/talos/cmanager_linux.py
@@ -82,7 +82,6 @@ def GetPrivateBytes(pids):
     for pid in pids:
         mapfile = "/proc/%s/maps" % pid
         with open(mapfile) as maps:
-
             private = 0
 
             for line in maps:
@@ -113,7 +112,6 @@ def GetResidentSize(pids):
         file = "/proc/%s/status" % pid
 
         with open(file) as status:
-
             for line in status:
                 if line.find("VmRSS") >= 0:
                     RSS += int(line.split()[1]) * 1024
diff --git a/testing/talos/talos/results.py b/testing/talos/talos/results.py
index 73ebd56ed349..801c18a0cc3f 100755
--- a/testing/talos/talos/results.py
+++ b/testing/talos/talos/results.py
@@ -40,7 +40,6 @@ class TalosResults(object):
         - output_formats: a dict mapping formats to a list of URLs
         """
         try:
-
             for key, urls in output_formats.items():
                 _output = output.Output(self, Results)
                 results = _output()
@@ -377,7 +376,6 @@ class BrowserLogResults(object):
 
         # parse the timestamps
         for attr, tokens in self.time_tokens:
-
             # parse the token contents
             value, _last_token = self.get_single_token(*tokens)
 
diff --git a/testing/talos/talos/run_tests.py b/testing/talos/talos/run_tests.py
index d1c7299429b1..64c8b2d3b69f 100755
--- a/testing/talos/talos/run_tests.py
+++ b/testing/talos/talos/run_tests.py
@@ -456,7 +456,6 @@ def make_comparison_result(base_and_reference_results):
     # each set of two results is actually a base test followed by the
     # reference test; we want to go through each set of base vs reference
     for x in range(0, len(base_and_reference_results.results[0].results), 2):
-
         # separate the 'base' and 'reference' result run values
         results = base_and_reference_results.results[0].results
         base_result_runs = results[x]["runs"]
diff --git a/testing/talos/talos/talosconfig.py b/testing/talos/talos/talosconfig.py
index a3f0d6f8070f..d3dc64cd0d8a 100644
--- a/testing/talos/talos/talosconfig.py
+++ b/testing/talos/talos/talosconfig.py
@@ -36,7 +36,6 @@ def generateTalosConfig(command_line, browser_config, test_config, pid=None):
         and ("xperf_user_providers" in test_config)
         and ("xperf_stackwalk" in test_config)
     ):  # noqa
-
         print("extending with xperf!")
         browser_config["xperf_providers"] = test_config["xperf_providers"]
         browser_config["xperf_user_providers"] = test_config["xperf_user_providers"]
diff --git a/testing/talos/talos/unittests/conftest.py b/testing/talos/talos/unittests/conftest.py
index 8b31038b752d..96cc9ca9b961 100644
--- a/testing/talos/talos/unittests/conftest.py
+++ b/testing/talos/talos/unittests/conftest.py
@@ -10,7 +10,6 @@ __TESTS_DIR = os.path.join(os.path.dirname(os.path.dirname(here)), "tests")
 
 def remove_develop_files(starting_dir=__TESTS_DIR):
     for file_name in os.listdir(starting_dir):
-
         file_path = os.path.join(starting_dir, file_name)
 
         if file_name.endswith(".develop") and os.path.isfile(file_path):
diff --git a/testing/talos/talos/xtalos/etlparser.py b/testing/talos/talos/xtalos/etlparser.py
index 10fa5c64d3d6..5bbfa913f5d5 100644
--- a/testing/talos/talos/xtalos/etlparser.py
+++ b/testing/talos/talos/xtalos/etlparser.py
@@ -610,7 +610,6 @@ def etlparser_from_config(config_file, **kwargs):
 
 
 def main(args=sys.argv[1:]):
-
     # parse command line arguments
     parser = xtalos.XtalosOptions()
     args = parser.parse_args(args)
diff --git a/testing/talos/talos/xtalos/parse_xperf.py b/testing/talos/talos/xtalos/parse_xperf.py
index 8daff86d6b84..eef9c7a9b189 100644
--- a/testing/talos/talos/xtalos/parse_xperf.py
+++ b/testing/talos/talos/xtalos/parse_xperf.py
@@ -107,7 +107,6 @@ def stop_from_config(config_file=None, debug=False, **kwargs):
 
 
 def main(args=sys.argv[1:]):
-
     # parse command line arguments
     parser = xtalos.XtalosOptions()
     args = parser.parse_args(args)
diff --git a/testing/talos/talos/xtalos/start_xperf.py b/testing/talos/talos/xtalos/start_xperf.py
index 5f4e12079645..87cc6dc029ac 100644
--- a/testing/talos/talos/xtalos/start_xperf.py
+++ b/testing/talos/talos/xtalos/start_xperf.py
@@ -18,7 +18,6 @@ def start(
     etl_filename,
     debug=False,
 ):
-
     xperf_cmd = [
         xperf_path,
         "-on",
@@ -86,7 +85,6 @@ def start_from_config(config_file=None, debug=False, **kwargs):
 
 
 def main(args=sys.argv[1:]):
-
     # parse command line options
     parser = xtalos.XtalosOptions()
     args = parser.parse_args(args)
diff --git a/testing/talos/talos/xtalos/xperf_analyzer.py b/testing/talos/talos/xtalos/xperf_analyzer.py
index 0d218fcda344..833dc9960a6e 100644
--- a/testing/talos/talos/xtalos/xperf_analyzer.py
+++ b/testing/talos/talos/xtalos/xperf_analyzer.py
@@ -306,7 +306,7 @@ class XPerfCounter(XPerfAttribute):
     def accumulate(self, evt):
         data = evt.get_whiteboard()
 
-        for (key, comp) in six.iteritems(self.filters):
+        for key, comp in six.iteritems(self.filters):
             try:
                 testdata = data[key]
             except KeyError:
@@ -335,7 +335,7 @@ class XPerfCounter(XPerfAttribute):
         )
         if self.values:
             msg += " with accumulated"
-            for (k, v) in six.iteritems(self.values):
+            for k, v in six.iteritems(self.values):
                 msg += " [[{!s}] == {!s}]".format((k), (v))
         return msg
 
diff --git a/testing/talos/talos/xtalos/xtalos.py b/testing/talos/talos/xtalos/xtalos.py
index 632fb59c4280..fad7afa0debb 100644
--- a/testing/talos/talos/xtalos/xtalos.py
+++ b/testing/talos/talos/xtalos/xtalos.py
@@ -154,7 +154,6 @@ class XtalosOptions(argparse.ArgumentParser):
         self.set_defaults(**defaults)
 
     def verifyOptions(self, options):
-
         # override options from config file
         if options.configFile:
             options_from_config(options.__dict__, options.configFile)
diff --git a/testing/tps/tps/firefoxrunner.py b/testing/tps/tps/firefoxrunner.py
index e82392c6c03f..7225ab960cbc 100644
--- a/testing/tps/tps/firefoxrunner.py
+++ b/testing/tps/tps/firefoxrunner.py
@@ -12,7 +12,6 @@ from mozrunner import FirefoxRunner
 
 
 class TPSFirefoxRunner(object):
-
     PROCESS_TIMEOUT = 240
 
     def __init__(self, binary):
diff --git a/testing/tps/tps/phase.py b/testing/tps/tps/phase.py
index f51cf9e4c692..af40664c36b7 100644
--- a/testing/tps/tps/phase.py
+++ b/testing/tps/tps/phase.py
@@ -7,7 +7,6 @@ import re
 
 
 class TPSTestPhase(object):
-
     lineRe = re.compile(
         r"^(.*?)test phase (?P<matchphase>[^\s]+): (?P<matchstatus>.*)$"
     )
@@ -63,7 +62,6 @@ class TPSTestPhase(object):
         found_test = False
         f = open(self.logfile, "r")
         for line in f:
-
             # skip to the part of the log file that deals with the test we're running
             if not found_test:
                 if line.find("Running test %s" % self.testname) > -1:
diff --git a/testing/tps/tps/testrunner.py b/testing/tps/tps/testrunner.py
index f18c89fe90c8..9c3c135311a9 100644
--- a/testing/tps/tps/testrunner.py
+++ b/testing/tps/tps/testrunner.py
@@ -45,7 +45,6 @@ class TempFile(object):
 
 
 class TPSTestRunner(object):
-
     extra_env = {
         "MOZ_CRASHREPORTER_DISABLE": "1",
         "GNOME_DISABLE_CRASH_DIALOG": "1",
@@ -425,7 +424,6 @@ class TPSTestRunner(object):
                 traceback.print_exc()
         else:
             try:
-
                 self.writeToResultFile(self.postdata)
             except Exception:
                 traceback.print_exc()
@@ -463,7 +461,7 @@ class TPSTestRunner(object):
             f.close()
             testfiles = json.loads(jsondata)
             testlist = []
-            for (filename, meta) in testfiles["tests"].items():
+            for filename, meta in testfiles["tests"].items():
                 skip_reason = meta.get("disabled")
                 if skip_reason:
                     print("Skipping test {} - {}".format(filename, skip_reason))
diff --git a/testing/web-platform/mozilla/tests/service-workers/resources/fetch_video.py b/testing/web-platform/mozilla/tests/service-workers/resources/fetch_video.py
index 541f00c01981..3945506f3037 100644
--- a/testing/web-platform/mozilla/tests/service-workers/resources/fetch_video.py
+++ b/testing/web-platform/mozilla/tests/service-workers/resources/fetch_video.py
@@ -2,7 +2,7 @@ import os
 
 
 def main(request, response):
-    filename = os.path.join(request.doc_root, u"media", u"2x2-green.ogv")
+    filename = os.path.join(request.doc_root, "media", "2x2-green.ogv")
     body = open(filename, "rb").read()
     length = len(body)
     headers = [
diff --git a/testing/webcompat/interventions/tests/test_1570108_steamcommunity.py b/testing/webcompat/interventions/tests/test_1570108_steamcommunity.py
index ee9e1f8e06a8..e76f6cabafca 100644
--- a/testing/webcompat/interventions/tests/test_1570108_steamcommunity.py
+++ b/testing/webcompat/interventions/tests/test_1570108_steamcommunity.py
@@ -32,7 +32,7 @@ async def do_2fa(client):
         client.await_element_hidden(loader)
     for digit in digits:
         if digit.property("value"):
-            digit.send_keys(u"\ue003")  # backspace
+            digit.send_keys("\ue003")  # backspace
 
     code = input("**** Enter two-factor authentication code: ")
     for i, digit in enumerate(code):
diff --git a/testing/webcompat/interventions/tests/test_1836109_watch_tonton_com_my.py b/testing/webcompat/interventions/tests/test_1836109_watch_tonton_com_my.py
index e005aa57840a..e36eaaa53a53 100644
--- a/testing/webcompat/interventions/tests/test_1836109_watch_tonton_com_my.py
+++ b/testing/webcompat/interventions/tests/test_1836109_watch_tonton_com_my.py
@@ -8,6 +8,7 @@ LOGIN_CSS = ".login-page-container"
 # The site can take a little time to load, and this includes
 # interstitial ads, so for now we give it 10 seconds.
 
+
 # Skip Android as the site blocks many Android devices including the emulator
 @pytest.mark.skip_platforms("android")
 @pytest.mark.asyncio
diff --git a/testing/xpcshell/runxpcshelltests.py b/testing/xpcshell/runxpcshelltests.py
index 75b5619b1a48..100b1bfd18b9 100755
--- a/testing/xpcshell/runxpcshelltests.py
+++ b/testing/xpcshell/runxpcshelltests.py
@@ -2012,10 +2012,10 @@ class XPCShellTests(object):
             maxTime = timedelta(seconds=options["verifyMaxTime"])
             for test_object in self.alltests:
                 stepResults = {}
-                for (descr, step) in steps:
+                for descr, step in steps:
                     stepResults[descr] = "not run / incomplete"
                 finalResult = "PASSED"
-                for (descr, step) in steps:
+                for descr, step in steps:
                     if (datetime.now() - startTime) > maxTime:
                         self.log.info(
                             "::: Test verification is taking too long: Giving up!"
diff --git a/toolkit/components/crashes/gen_CrashManager.py b/toolkit/components/crashes/gen_CrashManager.py
index 34cde771fe8f..7c0ba8ab9087 100644
--- a/toolkit/components/crashes/gen_CrashManager.py
+++ b/toolkit/components/crashes/gen_CrashManager.py
@@ -49,7 +49,7 @@ def main(o, crashManager):
     subst = [gen_process_map(), gen_process_pings()]
     with open(crashManager, "r") as src:
         for l in src.readlines():
-            for (id, value) in subst:
+            for id, value in subst:
                 if id in l:
                     l = l.replace(id, value)
             o.write(l)
diff --git a/toolkit/components/featuregates/gen_feature_definitions.py b/toolkit/components/featuregates/gen_feature_definitions.py
index 14cdad363745..da4a9fe177bb 100755
--- a/toolkit/components/featuregates/gen_feature_definitions.py
+++ b/toolkit/components/featuregates/gen_feature_definitions.py
@@ -143,7 +143,7 @@ def expand_feature(feature):
             new_key = hyphens_to_camel_case(key)
             key_changes.append((key, new_key))
 
-    for (old_key, new_key) in key_changes:
+    for old_key, new_key in key_changes:
         feature[new_key] = feature[old_key]
         del feature[old_key]
 
diff --git a/toolkit/components/featuregates/test/python/test_gen_feature_definitions.py b/toolkit/components/featuregates/test/python/test_gen_feature_definitions.py
index 0967e38de851..b6a3e4078910 100644
--- a/toolkit/components/featuregates/test/python/test_gen_feature_definitions.py
+++ b/toolkit/components/featuregates/test/python/test_gen_feature_definitions.py
@@ -271,27 +271,27 @@ class MainTests(unittest.TestCase):
         output.seek(0)
         results = json.load(output)
         assert results == {
-            u"demo-feature": {
-                u"id": u"demo-feature",
-                u"title": u"Demo Feature",
-                u"description": u"A no-op feature to demo the feature gate system.",
-                u"restartRequired": False,
-                u"preference": u"foo.bar.baz",
-                u"type": u"boolean",
-                u"bugNumbers": [1479127],
-                u"isPublic": {u"default": True},
-                u"defaultValue": {u"default": False},
+            "demo-feature": {
+                "id": "demo-feature",
+                "title": "Demo Feature",
+                "description": "A no-op feature to demo the feature gate system.",
+                "restartRequired": False,
+                "preference": "foo.bar.baz",
+                "type": "boolean",
+                "bugNumbers": [1479127],
+                "isPublic": {"default": True},
+                "defaultValue": {"default": False},
             },
-            u"minimal-feature": {
-                u"id": u"minimal-feature",
-                u"title": u"Minimal Feature",
-                u"description": u"The smallest feature that is valid",
-                u"restartRequired": True,
-                u"preference": u"features.minimal-feature.enabled",
-                u"type": u"boolean",
-                u"bugNumbers": [1479127],
-                u"isPublic": {u"default": False},
-                u"defaultValue": {u"default": None},
+            "minimal-feature": {
+                "id": "minimal-feature",
+                "title": "Minimal Feature",
+                "description": "The smallest feature that is valid",
+                "restartRequired": True,
+                "preference": "features.minimal-feature.enabled",
+                "type": "boolean",
+                "bugNumbers": [1479127],
+                "isPublic": {"default": False},
+                "defaultValue": {"default": None},
             },
         }
 
diff --git a/toolkit/components/glean/build_scripts/glean_parser_ext/jog.py b/toolkit/components/glean/build_scripts/glean_parser_ext/jog.py
index 36c4ddc08f65..f4d326a70a89 100644
--- a/toolkit/components/glean/build_scripts/glean_parser_ext/jog.py
+++ b/toolkit/components/glean/build_scripts/glean_parser_ext/jog.py
@@ -81,6 +81,7 @@ def load_monkeypatches():
     Monkeypatch jinja template loading because we're not glean_parser.
     We're glean_parser_ext.
     """
+
     # Monkeypatch util.get_jinja2_template to find templates nearby
     def get_local_template(template_name, filters=()):
         env = jinja2.Environment(
diff --git a/toolkit/components/glean/build_scripts/glean_parser_ext/js.py b/toolkit/components/glean/build_scripts/glean_parser_ext/js.py
index c1425c4ec946..d50adfc0fa7d 100644
--- a/toolkit/components/glean/build_scripts/glean_parser_ext/js.py
+++ b/toolkit/components/glean/build_scripts/glean_parser_ext/js.py
@@ -65,7 +65,7 @@ def ping_entry(ping_id, ping_string_index):
     The 2 pieces of information of a ping encoded into a single 32-bit integer.
     """
     assert ping_id < 2 ** (32 - PING_INDEX_BITS)
-    assert ping_string_index < 2 ** PING_INDEX_BITS
+    assert ping_string_index < 2**PING_INDEX_BITS
     return ping_id << PING_INDEX_BITS | ping_string_index
 
 
diff --git a/toolkit/components/glean/build_scripts/glean_parser_ext/string_table.py b/toolkit/components/glean/build_scripts/glean_parser_ext/string_table.py
index 1958eef604e3..2cf5cb68e783 100644
--- a/toolkit/components/glean/build_scripts/glean_parser_ext/string_table.py
+++ b/toolkit/components/glean/build_scripts/glean_parser_ext/string_table.py
@@ -79,7 +79,7 @@ class StringTable:
         f.write("#else\n")
         f.write("constexpr char %s[] = {\n" % name)
         f.write("#endif\n")
-        for (string, offset) in sorted(entries, key=lambda x: x[1]):
+        for string, offset in sorted(entries, key=lambda x: x[1]):
             if "*/" in string:
                 raise ValueError(
                     "String in string table contains unexpected sequence '*/': %s"
diff --git a/toolkit/components/nimbus/generate/generate_feature_manifest.py b/toolkit/components/nimbus/generate/generate_feature_manifest.py
index f9ee13dd5a07..86ed368be0b6 100644
--- a/toolkit/components/nimbus/generate/generate_feature_manifest.py
+++ b/toolkit/components/nimbus/generate/generate_feature_manifest.py
@@ -102,14 +102,14 @@ def generate_feature_manifest(fd, input_file):
         )
 
         fd.write(f"export const FeatureManifest = {json.dumps(manifest)};")
-    except (IOError) as e:
+    except IOError as e:
         print(f"{input_file}: error:\n  {e}\n")
         sys.exit(1)
 
 
 def platform_feature_manifest_array(features):
     entries = []
-    for (feature, featureData) in features.items():
+    for feature, featureData in features.items():
         # Features have to be tagged isEarlyStartup to be accessible
         # to Nimbus platform API
         if not featureData.get("isEarlyStartup", False):
@@ -147,6 +147,6 @@ def generate_platform_feature_manifest(fd, input_file):
         with open(input_file, "r", encoding="utf-8") as yaml_input:
             data = yaml.safe_load(yaml_input)
             fd.write(file_structure(data))
-    except (IOError) as e:
+    except IOError as e:
         print("{}: error:\n  {}\n".format(input_file, e))
         sys.exit(1)
diff --git a/toolkit/components/telemetry/build_scripts/gen_histogram_enum.py b/toolkit/components/telemetry/build_scripts/gen_histogram_enum.py
index 8f224c5140d1..6ee88904575e 100644
--- a/toolkit/components/telemetry/build_scripts/gen_histogram_enum.py
+++ b/toolkit/components/telemetry/build_scripts/gen_histogram_enum.py
@@ -66,7 +66,7 @@ def main(output, *filenames):
     # contiguous block.
     print("enum HistogramID : uint32_t {", file=output)
     seen_group_types = {"UseCounter": False, "UseCounterWorker": False}
-    for (group_type, histograms) in groups:
+    for group_type, histograms in groups:
         if group_type is not None:
             assert isinstance(group_type, str)
             assert group_type in seen_group_types.keys()
@@ -95,7 +95,7 @@ def main(output, *filenames):
 
     print("  HistogramCount,", file=output)
 
-    for (key, value) in sorted(seen_group_types.items()):
+    for key, value in sorted(seen_group_types.items()):
         if value:
             print(
                 "  Histogram{0}Count = HistogramLast{0} - HistogramFirst{0} + 1,".format(
diff --git a/toolkit/components/telemetry/build_scripts/mozparsers/parse_histograms.py b/toolkit/components/telemetry/build_scripts/mozparsers/parse_histograms.py
index cf7863ff5816..d530d37f82e8 100644
--- a/toolkit/components/telemetry/build_scripts/mozparsers/parse_histograms.py
+++ b/toolkit/components/telemetry/build_scripts/mozparsers/parse_histograms.py
@@ -962,7 +962,7 @@ def from_files(filenames, strict_type_checks=True):
         if not isinstance(histograms, OrderedDict):
             ParserError("Histogram parser did not provide an OrderedDict.").handle_now()
 
-        for (name, definition) in histograms.items():
+        for name, definition in histograms.items():
             if name in all_histograms:
                 ParserError('Duplicate histogram name "%s".' % name).handle_later()
             all_histograms[name] = definition
@@ -1005,5 +1005,5 @@ def from_files(filenames, strict_type_checks=True):
             )
             ParserError(msg % (", ".join(sorted(orphaned)))).handle_later()
 
-    for (name, definition) in all_histograms.items():
+    for name, definition in all_histograms.items():
         yield Histogram(name, definition, strict_type_checks=strict_type_checks)
diff --git a/toolkit/components/telemetry/tests/integration/tests/test_search_counts_across_sessions.py b/toolkit/components/telemetry/tests/integration/tests/test_search_counts_across_sessions.py
index c2d9720b002c..34afd305ad9e 100644
--- a/toolkit/components/telemetry/tests/integration/tests/test_search_counts_across_sessions.py
+++ b/toolkit/components/telemetry/tests/integration/tests/test_search_counts_across_sessions.py
@@ -62,11 +62,11 @@ def test_search_counts(browser, helpers):
     ]
 
     assert search_counts1 == {
-        u"range": [1, 2],
-        u"bucket_count": 3,
-        u"histogram_type": 4,
-        u"values": {u"1": 0, u"0": 1},
-        u"sum": 1,
+        "range": [1, 2],
+        "bucket_count": 3,
+        "histogram_type": 4,
+        "values": {"1": 0, "0": 1},
+        "sum": 1,
     }
 
     # - Install addon
@@ -157,11 +157,11 @@ def test_search_counts(browser, helpers):
         "{}.urlbar".format(search_engine)
     ]
     assert search_counts3 == {
-        u"range": [1, 2],
-        u"bucket_count": 3,
-        u"histogram_type": 4,
-        u"values": {u"1": 0, u"0": 3},
-        u"sum": 3,
+        "range": [1, 2],
+        "bucket_count": 3,
+        "histogram_type": 4,
+        "values": {"1": 0, "0": 3},
+        "sum": 3,
     }
 
 
diff --git a/toolkit/components/telemetry/tests/marionette/harness/telemetry_harness/testcase.py b/toolkit/components/telemetry/tests/marionette/harness/telemetry_harness/testcase.py
index b6f51e47b236..d30fd6798653 100644
--- a/toolkit/components/telemetry/tests/marionette/harness/telemetry_harness/testcase.py
+++ b/toolkit/components/telemetry/tests/marionette/harness/telemetry_harness/testcase.py
@@ -224,7 +224,7 @@ class TelemetryTestCase(WindowManagerMixin, MarionetteTestCase):
                 return TelemetryController.getCurrentPingData(true);
                 """
             )
-            return ping_data[u"payload"][u"info"][u"subsessionId"]
+            return ping_data["payload"]["info"]["subsessionId"]
 
     def tearDown(self, *args, **kwargs):
         """Stop the ping server and tear down the testcase."""
diff --git a/toolkit/components/telemetry/tests/marionette/tests/client/test_fog_user_activity.py b/toolkit/components/telemetry/tests/marionette/tests/client/test_fog_user_activity.py
index fec71476320f..35a662df1a4b 100644
--- a/toolkit/components/telemetry/tests/marionette/tests/client/test_fog_user_activity.py
+++ b/toolkit/components/telemetry/tests/marionette/tests/client/test_fog_user_activity.py
@@ -10,7 +10,6 @@ class TestClientActivity(FOGTestCase):
     """Tests for client activity and FOG's scheduling of the "baseline" ping."""
 
     def test_user_activity(self):
-
         # First test that restarting the browser sends a "active" ping
         ping0 = self.wait_for_ping(
             self.restart_browser, FOG_BASELINE_PING, ping_server=self.fog_ping_server
diff --git a/toolkit/components/telemetry/tests/python/test_gen_event_data_json.py b/toolkit/components/telemetry/tests/python/test_gen_event_data_json.py
index 3a2b374bf339..5caa4cebbc59 100644
--- a/toolkit/components/telemetry/tests/python/test_gen_event_data_json.py
+++ b/toolkit/components/telemetry/tests/python/test_gen_event_data_json.py
@@ -23,7 +23,6 @@ import gen_event_data  # noqa: E402
 
 
 class TestEventDataJson(unittest.TestCase):
-
     maxDiff = None
 
     def test_JSON_definitions_generation(self):
diff --git a/toolkit/components/telemetry/tests/python/test_gen_scalar_data_json.py b/toolkit/components/telemetry/tests/python/test_gen_scalar_data_json.py
index 1db5558a2efd..ac60e2ae1028 100644
--- a/toolkit/components/telemetry/tests/python/test_gen_scalar_data_json.py
+++ b/toolkit/components/telemetry/tests/python/test_gen_scalar_data_json.py
@@ -22,7 +22,6 @@ import gen_scalar_data  # noqa: E402
 
 
 class TestScalarDataJson(unittest.TestCase):
-
     maxDiff = None
 
     def test_JSON_definitions_generation(self):
diff --git a/toolkit/components/telemetry/tests/python/test_histogramtools_strict.py b/toolkit/components/telemetry/tests/python/test_histogramtools_strict.py
index accafe90adb9..2109cd7d35e4 100644
--- a/toolkit/components/telemetry/tests/python/test_histogramtools_strict.py
+++ b/toolkit/components/telemetry/tests/python/test_histogramtools_strict.py
@@ -158,7 +158,7 @@ class TestParser(unittest.TestCase):
                 "expires_in_version": "never",
                 "kind": "exponential",
                 "low": 1024,
-                "high": 2 ** 64,
+                "high": 2**64,
                 "n_buckets": 100,
                 "products": ["firefox"],
                 "description": "Test histogram",
@@ -515,7 +515,7 @@ class TestParser(unittest.TestCase):
                 "expires_in_version": "never",
                 "kind": "exponential",
                 "low": 1024,
-                "high": 2 ** 64,
+                "high": 2**64,
                 "n_buckets": 100,
                 "keyed": "true",
                 "description": "Test histogram",
diff --git a/toolkit/crashreporter/generate_crash_reporter_sources.py b/toolkit/crashreporter/generate_crash_reporter_sources.py
index 9d066a814c99..beefa2e2741b 100644
--- a/toolkit/crashreporter/generate_crash_reporter_sources.py
+++ b/toolkit/crashreporter/generate_crash_reporter_sources.py
@@ -21,7 +21,7 @@ template_header = (
 def validate_annotations(annotations):
     """Ensure that the annotations have all the required fields"""
 
-    for (name, data) in sorted(annotations.items()):
+    for name, data in sorted(annotations.items()):
         if "description" not in data:
             print("Annotation " + name + " does not have a description\n")
             sys.exit(1)
diff --git a/toolkit/crashreporter/tools/symbolstore.py b/toolkit/crashreporter/tools/symbolstore.py
index 5dd5570a848f..bc160025039e 100755
--- a/toolkit/crashreporter/tools/symbolstore.py
+++ b/toolkit/crashreporter/tools/symbolstore.py
@@ -306,7 +306,6 @@ if platform.system() == "Windows":
             ctypes.windll.kernel32.CloseHandle(handle)
         return result
 
-
 else:
     # Just use the os.path version otherwise.
     realpath = os.path.realpath
diff --git a/toolkit/moz.configure b/toolkit/moz.configure
index 46e2699270a6..c87034a19f78 100644
--- a/toolkit/moz.configure
+++ b/toolkit/moz.configure
@@ -4,6 +4,7 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
+
 # Set the MOZ_CONFIGURE_OPTIONS variable with all the options that
 # were passed somehow (environment, command line, mozconfig)
 @dependable
@@ -167,6 +168,7 @@ imply_option("--enable-profiling", dmd)
 imply_option("--enable-jemalloc", dmd, when=compile_environment)
 imply_option("--enable-replace-malloc", dmd, when=compile_environment)
 
+
 # midir-based Web MIDI support
 # ==============================================================
 @depends(target)
@@ -184,6 +186,7 @@ def midir_support(target, midir_linux_support):
 
 set_config("MOZ_WEBMIDI_MIDIR_IMPL", midir_support)
 
+
 # Enable various cubeb backends
 # ==============================================================
 @depends(target)
@@ -675,6 +678,7 @@ def freetype2_combined_info(fontconfig_info, freetype2_info):
 
 set_define("MOZ_HAVE_FREETYPE2", depends_if(freetype2_info)(lambda _: True))
 
+
 # Apple platform decoder support
 # ==============================================================
 @depends(toolkit)
@@ -804,6 +808,7 @@ def openmax(value):
 set_config("MOZ_OMX", openmax)
 set_define("MOZ_OMX", openmax)
 
+
 # EME Support
 # ==============================================================
 @depends(target, wmf)
@@ -1092,6 +1097,7 @@ set_config("NS_PRINTING", printing)
 set_define("NS_PRINTING", printing)
 set_define("NS_PRINT_PREVIEW", printing)
 
+
 # Speech-dispatcher support
 # ==============================================================
 @depends(toolkit)
@@ -1139,6 +1145,7 @@ def webspeech_test_backend(value):
 set_config("MOZ_WEBSPEECH_TEST_BACKEND", webspeech_test_backend)
 set_define("MOZ_WEBSPEECH_TEST_BACKEND", webspeech_test_backend)
 
+
 # Graphics
 # ==============================================================
 @depends(target, milestone)
@@ -1169,6 +1176,7 @@ system_webp = pkg_check_modules(
 
 set_config("MOZ_SYSTEM_WEBP", depends(when=system_webp)(lambda: True))
 
+
 # Build Freetype in the tree
 # ==============================================================
 @depends(target, "--enable-skia-pdf")
@@ -1728,10 +1736,13 @@ def midl_flags(flags, target, midl):
         return flags + ["-nologo", "-no_cpp", "-env", env]
 
     # widl
-    return flags + {
-        "x86": ["--win32", "-m32"],
-        "x86_64": ["--win64", "-m64"],
-    }[target.cpu]
+    return (
+        flags
+        + {
+            "x86": ["--win32", "-m32"],
+            "x86_64": ["--win64", "-m64"],
+        }[target.cpu]
+    )
 
 
 set_config("MIDL_FLAGS", midl_flags)
@@ -2751,6 +2762,7 @@ check_prog(
     when=compile_environment & target_is_windows,
 )
 
+
 # Fork server
 @depends(target, build_project)
 def forkserver_default(target, build_project):
@@ -3350,6 +3362,7 @@ check_header(
     when=target_has_linux_kernel & compile_environment,
 )
 
+
 # Smart card support
 # ==============================================================
 @depends(build_project)
diff --git a/toolkit/mozapps/installer/windows/nsis/preprocess-locale.py b/toolkit/mozapps/installer/windows/nsis/preprocess-locale.py
index 640ec5856439..280ab3d0855d 100644
--- a/toolkit/mozapps/installer/windows/nsis/preprocess-locale.py
+++ b/toolkit/mozapps/installer/windows/nsis/preprocess-locale.py
@@ -94,7 +94,7 @@ def preprocess_locale_files(config_dir, l10ndirs):
     fp = open_utf16le_file(join(config_dir, "baseLocale.nsh"))
     fp.write(
         (
-            u""";NSIS Modern User Interface - Language File
+            """;NSIS Modern User Interface - Language File
 ;Compatible with Modern UI 1.68
 ;Language: baseLocale (0)
 !insertmacro MOZ_MUI_LANGUAGEFILE_BEGIN \"baseLocale\"
@@ -106,7 +106,7 @@ def preprocess_locale_files(config_dir, l10ndirs):
         lookup("mui.properties", l10ndirs), "!define ", " ", True
     )
     fp.write(locale_strings.encode("utf-16-le"))
-    fp.write(u"!insertmacro MOZ_MUI_LANGUAGEFILE_END\n".encode("utf-16-le"))
+    fp.write("!insertmacro MOZ_MUI_LANGUAGEFILE_END\n".encode("utf-16-le"))
     fp.close()
 
     # Create the custom language file for our custom strings
@@ -149,7 +149,7 @@ def create_nlf_file(moz_dir, ab_cd, config_dir):
     fp = open_utf16le_file(join(config_dir, "baseLocale.nlf"))
     fp.write(
         (
-            u"""# Header, don't edit
+            """# Header, don't edit
 NLF v6
 # Start editing here
 # Language ID
diff --git a/toolkit/xre/dllservices/mozglue/gen_dll_blocklist_defs.py b/toolkit/xre/dllservices/mozglue/gen_dll_blocklist_defs.py
index 29fc42825933..1f053dfda6ac 100644
--- a/toolkit/xre/dllservices/mozglue/gen_dll_blocklist_defs.py
+++ b/toolkit/xre/dllservices/mozglue/gen_dll_blocklist_defs.py
@@ -393,7 +393,7 @@ GENERATED_BLOCKLIST_FILES = [
 
 class PETimeStamp(object):
     def __init__(self, ts):
-        max_timestamp = (2 ** 32) - 1
+        max_timestamp = (2**32) - 1
         if ts < 0 or ts > max_timestamp:
             raise ValueError("Invalid timestamp value")
         self._value = ts
@@ -713,7 +713,6 @@ def exec_script_file(script_name, globals):
 
 
 def gen_blocklists(first_fd, defs_filename):
-
     BlocklistDescriptor.set_output_fd(first_fd)
 
     # exec_env defines the global variables that will be present in the
diff --git a/tools/browsertime/mach_commands.py b/tools/browsertime/mach_commands.py
index 4850c82b75f7..8d0e0c3915cf 100644
--- a/tools/browsertime/mach_commands.py
+++ b/tools/browsertime/mach_commands.py
@@ -155,7 +155,7 @@ def visualmetrics_path():
 
 
 def host_platform():
-    is_64bits = sys.maxsize > 2 ** 32
+    is_64bits = sys.maxsize > 2**32
 
     if sys.platform.startswith("win"):
         if is_64bits:
diff --git a/tools/crashreporter/system-symbols/win/symsrv-fetch.py b/tools/crashreporter/system-symbols/win/symsrv-fetch.py
index beeaafa24514..be4bd101d525 100644
--- a/tools/crashreporter/system-symbols/win/symsrv-fetch.py
+++ b/tools/crashreporter/system-symbols/win/symsrv-fetch.py
@@ -78,7 +78,7 @@ def get_type(data):
 
 
 async def exp_backoff(retry_num):
-    await asyncio.sleep(2 ** retry_num)
+    await asyncio.sleep(2**retry_num)
 
 
 async def server_has_file(client, server, filename):
diff --git a/tools/github-sync/converter.py b/tools/github-sync/converter.py
index 57db9286c1b6..104229e29974 100755
--- a/tools/github-sync/converter.py
+++ b/tools/github-sync/converter.py
@@ -132,7 +132,7 @@ def get_real_base_hg_rev(hg_data, commit_map):
     # commit). The "tail" hg revisions are the ones for which we don't have their
     # ancestors in hg_data.
     tails = []
-    for (rev, cset) in hg_data.items():
+    for rev, cset in hg_data.items():
         for parent in cset.parents:
             if parent not in hg_data:
                 tails.append(rev)
@@ -245,7 +245,7 @@ def fake_commit(hg_rev, parent1, parent2):
 
 
 def build_tree(builder, treedata):
-    for (name, value) in treedata.items():
+    for name, value in treedata.items():
         if isinstance(value, dict):
             subbuilder = downstream_git_repo.TreeBuilder()
             build_tree(subbuilder, value)
@@ -269,7 +269,7 @@ def author_to_signature(author):
 def real_commit(hg_rev, parent1, parent2):
     filetree = dict()
     manifest = mozilla_hg_repo.manifest(rev=hg_rev)
-    for (nodeid, permission, executable, symlink, filename) in manifest:
+    for nodeid, permission, executable, symlink, filename in manifest:
         if not filename.startswith(relative_path.encode("utf-8")):
             continue
         if symlink:
@@ -460,12 +460,12 @@ if not hg_commits[hg_tip].touches_sync_code and len(hg_commits[hg_tip].parents)
     hg_tip = new_tip
 
 eprint("--- Interesting changesets ---")
-for (rev, cset) in hg_commits.items():
+for rev, cset in hg_commits.items():
     if cset.touches_sync_code or len(cset.parents) > 1 or rev in hg_to_git_commit_map:
         eprint(pretty_print(rev, cset))
 if DEBUG:
     eprint("--- Other changesets (not really interesting) ---")
-    for (rev, cset) in hg_commits.items():
+    for rev, cset in hg_commits.items():
         if not (
             cset.touches_sync_code
             or len(cset.parents) > 1
diff --git a/tools/jprof/split-profile.py b/tools/jprof/split-profile.py
index c280c130c23b..2e5fa89cafc1 100755
--- a/tools/jprof/split-profile.py
+++ b/tools/jprof/split-profile.py
@@ -145,7 +145,7 @@ generate_profile([], output_filename(0, None))
 # generate the listed splits
 count = 1
 excludes = []
-for (splitname, splitfunction) in splits:
+for splitname, splitfunction in splits:
     generate_profile(
         excludes + ["-i" + splitfunction], output_filename(count, splitname)
     )
diff --git a/tools/lint/android/lints.py b/tools/lint/android/lints.py
index e97a95e26583..53c86260137a 100644
--- a/tools/lint/android/lints.py
+++ b/tools/lint/android/lints.py
@@ -282,7 +282,6 @@ def _parse_checkstyle_output(config, topsrcdir=None, report_path=None):
     root = tree.getroot()
 
     for file in root.findall("file"):
-
         for error in file.findall("error"):
             # Like <error column="42" line="22" message="Name 'mPorts' must match pattern 'xm[A-Z][A-Za-z]*$'." severity="error" source="com.puppycrawl.tools.checkstyle.checks.naming.MemberNameCheck" />.  # NOQA: E501
             err = {
diff --git a/tools/lint/eslint/__init__.py b/tools/lint/eslint/__init__.py
index 9f1930d789b1..fdd7504c34c7 100644
--- a/tools/lint/eslint/__init__.py
+++ b/tools/lint/eslint/__init__.py
@@ -136,7 +136,6 @@ def lint(paths, config, binary=None, fix=None, rules=[], setup=None, **lintargs)
 
 
 def run(cmd_args, config):
-
     shell = False
     if (
         os.environ.get("MSYSTEM") in ("MINGW32", "MINGW64")
diff --git a/tools/lint/python/l10n_lint.py b/tools/lint/python/l10n_lint.py
index ef3269ef2aea..a16dc2626bc4 100644
--- a/tools/lint/python/l10n_lint.py
+++ b/tools/lint/python/l10n_lint.py
@@ -19,6 +19,7 @@ STRINGS_REPO = "https://hg.mozilla.org/l10n/gecko-strings"
 
 PULL_AFTER = timedelta(days=2)
 
+
 # Wrapper to call lint_strings with mozilla-central configuration
 # comm-central defines its own wrapper since comm-central strings are
 # in separate repositories
diff --git a/tools/lint/test/test_black.py b/tools/lint/test/test_black.py
index 9027670665a7..df0e792e68ae 100644
--- a/tools/lint/test/test_black.py
+++ b/tools/lint/test/test_black.py
@@ -11,7 +11,6 @@ fixed = 0
 
 
 def test_lint_fix(lint, create_temp_file):
-
     contents = """def is_unique(
                s
                ):
diff --git a/tools/lint/test/test_clang_format.py b/tools/lint/test/test_clang_format.py
index 809280601d55..d32e000131a2 100644
--- a/tools/lint/test/test_clang_format.py
+++ b/tools/lint/test/test_clang_format.py
@@ -123,7 +123,6 @@ def test_dir(lint, config, paths):
 
 
 def test_fixed(lint, create_temp_file):
-
     contents = """int  main ( ) { \n
 return 0; \n
 
diff --git a/tools/lint/test/test_file_whitespace.py b/tools/lint/test/test_file_whitespace.py
index 51b6fc479529..7dc815d6ca5f 100644
--- a/tools/lint/test/test_file_whitespace.py
+++ b/tools/lint/test/test_file_whitespace.py
@@ -33,7 +33,6 @@ def test_lint_file_whitespace(lint, paths):
 
 
 def test_lint_file_whitespace_fix(lint, paths, create_temp_file):
-
     contents = """int main() {  \n
     return 0;  \n
 }
diff --git a/tools/lint/test/test_perfdocs.py b/tools/lint/test/test_perfdocs.py
index 3e52e8627150..4ee834ad6897 100644
--- a/tools/lint/test/test_perfdocs.py
+++ b/tools/lint/test/test_perfdocs.py
@@ -549,7 +549,7 @@ def test_perfdocs_verifier_nonexistent_documented_metrics(
         verifier.validate_tree()
 
     assert len(logger.warning.call_args_list) == expected
-    for (args, _) in logger.warning.call_args_list:
+    for args, _ in logger.warning.call_args_list:
         assert "Cannot find documented metric" in args[0]
         assert "being used" in args[0]
 
@@ -604,7 +604,7 @@ def test_perfdocs_verifier_undocumented_metrics(
         verifier.validate_tree()
 
     assert len(logger.warning.call_args_list) == 1
-    for (args, _) in logger.warning.call_args_list:
+    for args, _ in logger.warning.call_args_list:
         assert "Missing description for the metric" in args[0]
 
 
@@ -668,7 +668,7 @@ def test_perfdocs_verifier_duplicate_metrics(
         verifier.validate_tree()
 
     assert len(logger.warning.call_args_list) == expected
-    for (args, _) in logger.warning.call_args_list:
+    for args, _ in logger.warning.call_args_list:
         assert "Duplicate definitions found for " in args[0]
 
 
diff --git a/tools/lint/test/test_rustfmt.py b/tools/lint/test/test_rustfmt.py
index c176a2695dbc..f1793be38301 100644
--- a/tools/lint/test/test_rustfmt.py
+++ b/tools/lint/test/test_rustfmt.py
@@ -41,7 +41,6 @@ def test_dir(lint, config, paths):
 
 
 def test_fix(lint, create_temp_file):
-
     contents = """fn main() {
     // Statements here are executed when the compiled binary is called
 
diff --git a/tools/lint/test/test_updatebot.py b/tools/lint/test/test_updatebot.py
index 55842e99c0e6..5763cc1a7ab0 100644
--- a/tools/lint/test/test_updatebot.py
+++ b/tools/lint/test/test_updatebot.py
@@ -9,7 +9,7 @@ def test_basic(lint, paths):
     results = []
 
     for p in paths():
-        for (root, dirs, files) in os.walk(p):
+        for root, dirs, files in os.walk(p):
             for f in files:
                 if f == ".yamllint":
                     continue
diff --git a/tools/moztreedocs/upload.py b/tools/moztreedocs/upload.py
index fadbe1418185..a60713517442 100644
--- a/tools/moztreedocs/upload.py
+++ b/tools/moztreedocs/upload.py
@@ -71,7 +71,6 @@ def get_s3_keys(s3, bucket):
 
 
 def s3_set_redirects(redirects):
-
     s3, bucket = create_aws_session()
 
     configuration = {"IndexDocument": {"Suffix": "index.html"}, "RoutingRules": []}
diff --git a/tools/rb/find_leakers.py b/tools/rb/find_leakers.py
index 9e9a37ac69a9..f131a2be59ef 100755
--- a/tools/rb/find_leakers.py
+++ b/tools/rb/find_leakers.py
@@ -50,7 +50,13 @@ def process_log(log_lines):
         if not log_line.startswith("<"):
             continue
 
-        (class_name, obj, ignore, operation, count,) = log_line.strip("\r\n").split(
+        (
+            class_name,
+            obj,
+            ignore,
+            operation,
+            count,
+        ) = log_line.strip("\r\n").split(
             " "
         )[:5]
 
diff --git a/tools/tryselect/selectors/release.py b/tools/tryselect/selectors/release.py
index a828b3d03864..ef43c2ae5785 100644
--- a/tools/tryselect/selectors/release.py
+++ b/tools/tryselect/selectors/release.py
@@ -130,7 +130,7 @@ def run(
         migration_configs = yaml.safe_load(f)
     for migration in migrations:
         migration_config = migration_configs["merge-automation"]["behaviors"][migration]
-        for (path, from_, to) in migration_config["replacements"]:
+        for path, from_, to in migration_config["replacements"]:
             if path in files_to_change:
                 contents = files_to_change[path]
             else:
diff --git a/tools/tryselect/selectors/syntax.py b/tools/tryselect/selectors/syntax.py
index ad643f831474..51e8e7d07524 100644
--- a/tools/tryselect/selectors/syntax.py
+++ b/tools/tryselect/selectors/syntax.py
@@ -285,7 +285,6 @@ def parse_arg(arg):
 
 
 class AutoTry:
-
     # Maps from flavors to the job names needed to run that flavour
     flavor_jobs = {
         "mochitest": ["mochitest-1", "mochitest-e10s-1"],
diff --git a/tools/tryselect/task_config.py b/tools/tryselect/task_config.py
index b63df0b709f0..d6c7996ef2e4 100644
--- a/tools/tryselect/task_config.py
+++ b/tools/tryselect/task_config.py
@@ -50,7 +50,6 @@ class TryConfig:
 
 
 class Artifact(TryConfig):
-
     arguments = [
         [
             ["--artifact"],
@@ -173,7 +172,6 @@ class Pernosco(TryConfig):
 
 
 class Path(TryConfig):
-
     arguments = [
         [
             ["paths"],
@@ -208,7 +206,6 @@ class Path(TryConfig):
 
 
 class Environment(TryConfig):
-
     arguments = [
         [
             ["--env"],
@@ -246,7 +243,6 @@ class RangeAction(Action):
 
 
 class Rebuild(TryConfig):
-
     arguments = [
         [
             ["--rebuild"],
@@ -300,7 +296,6 @@ class Routes(TryConfig):
 
 
 class ChemspillPrio(TryConfig):
-
     arguments = [
         [
             ["--chemspill-prio"],
@@ -423,7 +418,6 @@ class Browsertime(TryConfig):
 
 
 class DisablePgo(TryConfig):
-
     arguments = [
         [
             ["--disable-pgo"],
@@ -442,7 +436,6 @@ class DisablePgo(TryConfig):
 
 
 class WorkerOverrides(TryConfig):
-
     arguments = [
         [
             ["--worker-override"],
diff --git a/tools/tryselect/util/estimates.py b/tools/tryselect/util/estimates.py
index 634b1de2a215..a15ad7283116 100644
--- a/tools/tryselect/util/estimates.py
+++ b/tools/tryselect/util/estimates.py
@@ -38,7 +38,6 @@ def find_all_dependencies(graph, tasklist):
 
 
 def find_longest_path(graph, tasklist, duration_data):
-
     dep_durations = dict()
 
     def find_dependency_durations(task):
@@ -60,7 +59,6 @@ def find_longest_path(graph, tasklist, duration_data):
 
 
 def determine_percentile(quantiles_file, duration):
-
     duration = duration.total_seconds()
 
     with open(quantiles_file) as f:
diff --git a/tools/update-programs/moz.configure b/tools/update-programs/moz.configure
index 2b507519058a..1ce4a4ade9d4 100644
--- a/tools/update-programs/moz.configure
+++ b/tools/update-programs/moz.configure
@@ -2,6 +2,7 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
+
 # Spoof a stub of `js/moz.configure` for the included scripts.
 @dependable
 def js_standalone():
diff --git a/xpcom/build/Services.py b/xpcom/build/Services.py
index 4c6c14807fb5..43f010d05be7 100644
--- a/xpcom/build/Services.py
+++ b/xpcom/build/Services.py
@@ -83,7 +83,7 @@ def services_h(output):
 """
     )
 
-    for (name, iface, contractid) in services:
+    for name, iface, contractid in services:
         # Write out a forward declaration for the type in question
         segs = iface.split("::")
         for namespace in segs[:-1]:
@@ -126,7 +126,7 @@ def services_cpp(output):
     )
     output.write(CPP_INCLUDES)
 
-    for (name, iface, contractid) in services:
+    for name, iface, contractid in services:
         output.write(
             """
 static %(type)s* g%(name)s = nullptr;
@@ -165,6 +165,6 @@ mozilla::services::Shutdown()
   gXPCOMShuttingDown = true;
 """
     )
-    for (name, iface, contractid) in services:
+    for name, iface, contractid in services:
         output.write("  NS_IF_RELEASE(g%s);\n" % name)
     output.write("}\n")
diff --git a/xpcom/ds/tools/perfecthash.py b/xpcom/ds/tools/perfecthash.py
index b4e964a125e8..929b643a309d 100644
--- a/xpcom/ds/tools/perfecthash.py
+++ b/xpcom/ds/tools/perfecthash.py
@@ -291,8 +291,9 @@ class CGHelper(object):
         if return_type is None:
             return_type = "const %s&" % self.entry_type
 
-        return textwrap.dedent(
-            """
+        return (
+            textwrap.dedent(
+                """
             %(return_type)s
             %(name)s(%(key_type)s aKey)
             {
@@ -305,16 +306,18 @@ class CGHelper(object):
               %(return_entry)s
             }
             """
-        ) % {
-            "name": name,
-            "basis_table": self._indent(self.basis_table()),
-            "entries_name": self.entries_name,
-            "return_type": return_type,
-            "return_entry": self._indent(return_entry),
-            "key_type": key_type,
-            "key_bytes": key_bytes,
-            "key_length": key_length,
-        }
+            )
+            % {
+                "name": name,
+                "basis_table": self._indent(self.basis_table()),
+                "entries_name": self.entries_name,
+                "return_type": return_type,
+                "return_entry": self._indent(return_entry),
+                "key_type": key_type,
+                "key_bytes": key_bytes,
+                "key_length": key_length,
+            }
+        )
 
     def gen_jslinearstr_getter(
         self, name, return_type=None, return_entry="return entry;"
@@ -337,8 +340,9 @@ class CGHelper(object):
         if return_type is None:
             return_type = "const %s&" % self.entry_type
 
-        return textwrap.dedent(
-            """
+        return (
+            textwrap.dedent(
+                """
             %(return_type)s
             %(name)s(JSLinearString* aKey)
             {
@@ -362,10 +366,12 @@ class CGHelper(object):
               }
             }
             """
-        ) % {
-            "name": name,
-            "basis_table": self._indent(self.basis_table()),
-            "entries_name": self.entries_name,
-            "return_type": return_type,
-            "return_entry": self._indent(return_entry, 2),
-        }
+            )
+            % {
+                "name": name,
+                "basis_table": self._indent(self.basis_table()),
+                "entries_name": self.entries_name,
+                "return_type": return_type,
+                "return_entry": self._indent(return_entry, 2),
+            }
+        )
diff --git a/xpcom/idl-parser/xpidl/header.py b/xpcom/idl-parser/xpidl/header.py
index 80674d0b7684..ed179b1bad2a 100644
--- a/xpcom/idl-parser/xpidl/header.py
+++ b/xpcom/idl-parser/xpidl/header.py
@@ -21,7 +21,6 @@ if printdoccomments:
         for c in clist:
             fd.write("%s%s\n" % (indent, c))
 
-
 else:
 
     def printComments(fd, clist, indent):
diff --git a/xpcom/idl-parser/xpidl/rust.py b/xpcom/idl-parser/xpidl/rust.py
index 3b15387ddf71..b9fc6627fbfa 100644
--- a/xpcom/idl-parser/xpidl/rust.py
+++ b/xpcom/idl-parser/xpidl/rust.py
@@ -145,7 +145,6 @@ if printdoccomments:
         s += "\n/// ```\n///\n"
         return s
 
-
 else:
 
     def printComments(fd, clist, indent):
diff --git a/xpcom/idl-parser/xpidl/xpidl.py b/xpcom/idl-parser/xpidl/xpidl.py
index 3a5fc497319e..b95fd14bc510 100755
--- a/xpcom/idl-parser/xpidl/xpidl.py
+++ b/xpcom/idl-parser/xpidl/xpidl.py
@@ -1023,8 +1023,8 @@ class ConstMember(object):
         # Value is a lambda. Resolve it.
         self.value = self.valueFn(self.iface)
 
-        min_val = -(2 ** 31) if basetype.signed else 0
-        max_val = 2 ** 31 - 1 if basetype.signed else 2 ** 32 - 1
+        min_val = -(2**31) if basetype.signed else 0
+        max_val = 2**31 - 1 if basetype.signed else 2**32 - 1
         if self.value < min_val or self.value > max_val:
             raise IDLError(
                 "xpidl constants must fit within %s"
diff --git a/xpcom/reflect/xptcall/md/unix/moz.build b/xpcom/reflect/xptcall/md/unix/moz.build
index e74c936c3852..ab0d1c32ecad 100644
--- a/xpcom/reflect/xptcall/md/unix/moz.build
+++ b/xpcom/reflect/xptcall/md/unix/moz.build
@@ -28,19 +28,15 @@ if CONFIG["OS_ARCH"] == "GNU":
     if CONFIG["CPU_ARCH"] == "x86":
         SOURCES += ["xptcinvoke_gcc_x86_unix.cpp", "xptcstubs_gcc_x86_unix.cpp"]
 
-if (
-    CONFIG["OS_ARCH"]
-    in (
-        "Linux",
-        "Bitrig",
-        "DragonFly",
-        "FreeBSD",
-        "NetBSD",
-        "OpenBSD",
-        "SunOS",
-    )
-    or CONFIG["OS_ARCH"].startswith("GNU_")
-):
+if CONFIG["OS_ARCH"] in (
+    "Linux",
+    "Bitrig",
+    "DragonFly",
+    "FreeBSD",
+    "NetBSD",
+    "OpenBSD",
+    "SunOS",
+) or CONFIG["OS_ARCH"].startswith("GNU_"):
     if CONFIG["CPU_ARCH"] == "x86_64":
         SOURCES += [
             "xptcinvoke_asm_x86_64_unix.S",
diff --git a/xpcom/reflect/xptinfo/xptcodegen.py b/xpcom/reflect/xptinfo/xptcodegen.py
index 34131f6678ef..d2859703b86f 100644
--- a/xpcom/reflect/xptinfo/xptcodegen.py
+++ b/xpcom/reflect/xptinfo/xptcodegen.py
@@ -148,7 +148,7 @@ def iid_bytes(iid):  # Get the byte representation of the IID for hashing.
 
 # Split a 16-bit integer into its high and low 8 bits
 def splitint(i):
-    assert i < 2 ** 16
+    assert i < 2**16
     return (i >> 8, i & 0xFF)