python - парсинг и операции над строкой - номером версии

>может сравнить два номера

По какому принципу?

distutils.version.StrictVersion - Version numbering for anal retentives and software idealists.

distutils.version.LooseVersion - Version numbering for anarchists and software realists.

portage # emerge dev-lang/python-3.1.2-r4
!!! 'dev-lang/python-3.1.2-r4' is not a valid package atom.
!!! Please check ebuild(5) for full details.

oops, that for software maniacs