[Python-ideas] A library for the deprecation of a function/class

[Stéphane Wirtel]

With the CPython sprint, I was thinking about a lib to mark a 
function/class as deprecated.

Example:

#!/usr/bin/env python
import sys
import deprecation  # from an external lib or from a stdlib module

__version__ = (1,0)

@deprecation.deprecated(python=(3,7,), msg='use foo_v2')
def foo():
	pass

@deprecation.deprecated(program=(1,2), msg='use bar_v2')
def bar():
	pass

@deprecation.deprecated(python=(3,7), msg='use inspect.signature()')
@deprecation.deprecated(python=(3,7), to_use=inspect.signature)
def getfullargspec(*args, **kwargs):
	pass

The deprecated decorator should check the version of the software and 
the version of Python if asked with the arguments.
it will raise warnings.warn with PendingDeprecationWarning or 
DeprecationWarning. Can be used in the documentation, via introspection.

It's just an idea, there is no code, no specs but if you are interested 
I think I can try to propose a real solution
with an external library and if this idea seems to be interesting, I 
will propose a PEP for 3.5 or 3.6.

The interest of this lib, we can parse the source code and find the 
deprecated functions/classes with a small tool and the maintenance of 
the code should be improved.

Please, could you give me your feedback?

Thank you,

Stephane

--
Stéphane Wirtel - http://wirtel.be - @matrixise