[Python-Dev] PEP 435 -- Adding an Enum type to the Python standard library

Steven D'Aprano steve at pearwood.info
Fri Apr 26 07:01:06 CEST 2013


On 26/04/13 13:22, Greg wrote:
> On 26/04/2013 3:12 p.m., Glenn Linderman wrote:
>> On 4/25/2013 7:49 PM, Nick Coghlan wrote:
>
>>> You couldn't create an enum of callables, but that would be a
>>> seriously weird thing to do anyway....
>>
>> But aren't all classes callable?
>
> An enum of classes would be seriously weird as well, I think.


I don't think iscallable will work, since that descriptors like
staticmethod and classmethod aren't callable. Nor are properties.


I think a solution may be an explicit decorator that tells the
metaclass not to skip the object into an enum value:


class Insect(enum.Enum):
     ant = 1
     bee = 2

     @enum.skip
     @classmethod
     def spam(cls, args):
         pass


assert isinstance(Insect.spam, classmethod)



One side effect of this is that now you can (ab)use the decorator
to have regular data attributes. Whether that counts as a good
thing or a bad thing, I leave up to others to decide...




-- 
Steven


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