Frazer McLean noticed that even though the version parsing regex in
PEP 440 Appendix B was explicitly restricted to ASCII digits, the
is_canonical regex was more permissive and nominally allowed
arbitrary Unicode [Nd] characters.
The restrictive interpretation was the correct one (and reflects what
tools actually support), so I've merged Frazer's change at
to fix the omission and update the
is_canonical regex to be
consistent with the version parsing one.
-- Nick Coghlan | email@example.com | Brisbane, Australia