RFE: PyPI (PEP 440) versioning scheme

[encukou]

Anitya currently supports RPM, calver and semver schemes.
Python packages (as available on on PyPI and installed by pip) use the PEP 440 versioning scheme, which is unfortunately slightly different in the details (pre-releases, in particular).

The specification is implemented in the Python module packaging.version (but could be reimplemented if necessary).

Would it be worth it to add this to anitya?
Is there anything to watch out for if I want to write the PR (apart from general stuff in the Development Guide)?

Last but not least, thank you for Anitya! the-new-hotness saves us (Red Hat Python-maint team) a lot of time for Fedora maintenance – we use it so much that this bit of missing functionality is starting to be annoying :)

[Zlopez]

I didn't know the PyPI has they own versioning scheme. Could be nice to have it in Anitya.

If you want to create a PR for it, just follow the development guide. In this case you need to add a new class to anitya.lib.versions and it should work as expected.