WoefulDerelict [1] filed a deletion request for python2-enum [2]:

This package no longer has any dependencies in the AUR as they have all been ported to python2-enum34. It should be safe to remove.

[1] https://aur.archlinux.org/account/WoefulDerelict/ [2] https://aur.archlinux.org/pkgbase/python2-enum/