Post release spelling not recognized

[toabctl]

Hi,

According to https://www.python.org/dev/peps/pep-0440/#post-release-spelling , versions like '1.0-r4' should be normalized to '1.0.post4'. But running a simple test, this does not work:

$ python
Python 2.7.10 (default, May 24 2015, 14:46:10) [GCC] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import packaging
>>> packaging.__version__
'15.1'
>>> from packaging.version import parse
>>> v1 = parse('1.0.post4')
>>> v2 = parse('1.0.post4')
>>> v1 == v2
True
>>> v2 = parse('1.0.r4')
>>> v1 == v2
False
>>> 

[toabctl]

@dstufft comments?