Ethan, the suggestion has come up several times about using a dummy value such as the empty tuple to do autonumbering, thus looking more Pythonic.  I'm not a huge fan of the empty tuple, and I'm still not sure whether we need this, but I wonder if it would be possible to not have a new base class, but to put the smarts in the value to which the enums were assigned.  E.g. is this possible (a separate question than whether it's good :):

from enum import Enum, auto

class Color(Enum):
    red = auto
    green = auto
    blue = auto

Apologies if this has already been suggested; this tracker thread is too long to read the whole thing. :(