[Python-Dev] PEP 435 - ref impl disc 2 (original) (raw)

Glenn Linderman v+python at g.nevcal.com
Mon May 6 04:46:55 CEST 2013

On 5/5/2013 7:14 PM, Nick Coghlan wrote:

I think there comes a point where "subclass the metaclass" is the right answer to "how do I do X with this type?". I believe making two different kinds of value labelling mechanisms play nice is such a case :)

Could be.

Could be that sufficient operators added to an IntEnum subclass might work too. Although it might be unexpected that adding two enumeration members would produce a NamedInt :) But of course, if the enumeration were defined by NamedIntEnum, it might be less surprising.

On the other hand, if Enum is in stdlib, and lots of flags parameters get defined with Enum, then it would be a pain in the neck to redefine them with NamedIntEnum, so that debugging of flag combinations is easier. There are enough flag parameters in the stdlib APIs to make me think this would be a deficiency.

Sadly, once the Enums are defined, there is to be no way to subclass them to add functionality, like producing a NamedInt result from operations on them. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.python.org/pipermail/python-dev/attachments/20130505/690aa71b/attachment.html>

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