[Python-Dev] PEP 435 -- Adding an Enum type to the Python standard library (original) (raw)

Tim Delaney timothy.c.delaney at gmail.com
Mon Apr 22 02:55:05 CEST 2013

On 22 April 2013 10:31, Barry Warsaw <barry at python.org> wrote:

On Apr 22, 2013, at 09:31 AM, Tim Delaney wrote:

>I'm fine with iteration order being by sorted name by default, so long as >it's easily overrideable by enum subclasses or metaclasses e.g. an IntEnum >should probably iterate in value order. It does. :)

I knew it did, but wasn't sure if with the current discussion it was going to continue to do so.

>For definition order, a 3.x-only metaclass could be provided: > >class Days(enum.Enum, metaclass=enum.DefinitionOrder): > Monday = 1 > Tuesday = 2 > Wednesday = 3 > Thursday = 4 > Friday = 5 > Saturday = 6 > Sunday = 7

Yep, that's how it works. From flufl.enum: class IntEnumMetaclass(EnumMetaclass): # Define an iteration over the integer values instead of the attribute # names. def iter(cls): for key in sorted(cls.enums): yield getattr(cls, cls.enums[key])

Would it be worthwhile storing a sorted version of the enum keys here? Or do you think the current space vs speed tradeoff is better?

I need to grab the current flufl.enum code and see if I can easily extend it to do some more esoteric things that my enum implementation supports (not bare names, but maybe the name = ... syntax, which of course requires the definition order metaclass). I'm in the middle of a release cycle, so my time is somewhat limited right now :(

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