* Fix tube.clean_and_log not logging buffered data
Only new data received after the `clean_and_log` call is printed while
data already received and buffered earlier is not.
Print the buffered data first before waiting for more so we don't miss
anything.
* Only show buffered data if DEBUG is off
* Update CHANGELOG.md
---------
Co-authored-by: Arusekk <[email protected]>
* Import ABC from collections.abc for Python 3.
* Fix deprecation warnings due to invalid escape sequences.
* Use raw strings instead of escaping individually.
* Travis CI: Use flake8 to detect syntax errors
Repeat #1305 on the Python 3 branch. Also, remove the hardcoding of default values for dist and Py2.
https://flake8.pycqa.org/en/latest/user/error-codes.html
On the flake8 test selection, this PR does _not_ focus on "_style violations_" (the majority of flake8 error codes that [__psf/black__](https://github.com/psf/black) can autocorrect). Instead these tests are focus on runtime safety and correctness:
* E9 tests are about Python syntax errors usually raised because flake8 can not build an Abstract Syntax Tree (AST). Often these issues are a sign of unused code or code that has not been ported to Python 3. These would be compile-time errors in a compiled language but in a dynamic language like Python they result in the script halting/crashing on the user.
* F63 tests are usually about the confusion between identity and equality in Python. Use ==/!= to compare str, bytes, and int literals is the classic case. These are areas where __a == b__ is True but __a is b__ is False (or vice versa). Python >= 3.8 will raise SyntaxWarnings on these instances.
* F7 tests logic errors and syntax errors in type hints
* F82 tests are almost always _undefined names_ which are usually a sign of a typo, missing imports, or code that has not been ported to Python 3. These also would be compile-time errors in a compiled language but in Python a __NameError__ is raised which will halt/crash the script on the user.
* Fail fast, exclude generated source files
* --select=E9,F63,F7
* 2to3 -f print -wn examples
* No more <> in python 3.
