The `load` and `load_all` methods will issue a warning when they are
called without the 'Loader=' parameter. The warning will point to a URL
that is always up to date with the latest information on the usage of
`load`.
There are several ways to stop the warning:
* Use `full_load(input)` - sugar for `yaml.load(input, FullLoader)`
* FullLoader is the new safe but complete loader class
* Use `safe_load(input)` - sugar for `yaml.load(input, SafeLoader)`
* Make sure your input YAML consists of the 'safe' subset
* Use `unsafe_load(input)` - sugar for `yaml.load(input, UnsafeLoader)`
* Make sure your input YAML consists of the 'safe' subset
* Use `yaml.load(input, Loader=yaml.<loader>)`
* Or shorter `yaml.load(input, yaml.<loader>)`
* Where '<loader>' can be:
* FullLoader - safe, complete Python YAML loading
* SafeLoader - safe, partial Python YAML loading
* UnsafeLoader - more explicit name for the old, unsafe 'Loader' class
* yaml.warnings({'YAMLLoadWarning': False})
* Use this when you use third party modules that use `yaml.load(input)`
* Only do this if input is trusted
The above `load()` expressions all have `load_all()` counterparts.
You can get the original unsafe behavior with:
* `yaml.unsafe_load(input)`
* `yaml.load(input, Loader=yaml.UnsafeLoader)`
In a future release, `yaml.load(input)` will raise an exception.
The new loader called FullLoader is almost entirely complete as
Loader/UnsafeLoader but it does it avoids all known code execution
paths. It is the preferred YAML loader, and the current default for
`yaml.load(input)` when you get the warning.
Here are some of the exploits that can be triggered with UnsafeLoader
but not with FullLoader:
```
python -c 'import os, yaml; yaml.full_load("!!python/object/new:os.system [echo EXPLOIT!]")'`
python -c 'import yaml; print yaml.full_load("!!python/object/new:abs [-5]")'
python -c 'import yaml; yaml.full_load("!!python/object/new:eval [exit(5)]")' ; echo $?
python -c 'import yaml; yaml.full_load("!!python/object/new:exit [5]")' ; echo $?
Change yaml.load/yaml.dump to be yaml.safe_load/yaml.safe_dump, introduced yaml.danger_dump/yaml.danger_load, and the same for various other classes.
(python2 only at this moment)
Refs #5
Hold references to the objects being represented (should fix#22).
The value of a mapping node is represented as a list of pairs `(key, value)`
now.
Sort dictionary items (fix#23).
Recursive structures are now loaded and dumped correctly, including complex
structures like recursive tuples (fix#5). Thanks Peter Murphy for the patches.
To make it possible, representer functions are allowed to be generators.
In this case, the first generated value is an object. Other values produced
by the representer are ignored.
Make Representer not try to guess `!!pairs` when a list is represented.
You need to construct a `!!pairs` node explicitly now.
Do not check for duplicate mapping keys as it didn't work correctly anyway.
The line number is not calculated correctly for DOS-style line breaks.
Fix error reporting in '''remove_possible_simple_key'''. The problem is caused by the document:
{{{
+foo: &A bar
+*A ]
}}}
Raise an error for a complex key which is not indented correctly, for instance:
{{{
? "foo"
: "bar"
}}}
