On Wed, May 1, 2013 at 9:18 AM, Tres Seaver
I'd be glad to drop both of those in favor of subclassing: I think the emphasis on "class-ness" makes no sense, given the driving usecases for adopting enums into the stdlib in the first place. IOW, I would vote that real-world usecases trump hypothetical purity.
Yeah, this is the dilemma. But what *are* the real-world use cases? Please provide some. Here's how I would implement "extending" an enum if subclassing were not allowed: class Color(Enum): red = 1 white = 2 blue = 3 class ExtraColor(Enum): orange = 4 yellow = 5 green = 6 flag_colors = set(Color) | set(ExtraColor) Now I can test "c in flag_colors" to check whether c is a flag color. I can also loop over flag_colors. If I want the colors in definition order I could use a list instead: ordered_flag_colors = list(Color) + list(ExtraColor) But this would be less or more acceptable depending on whether it is a common or esoteric use case. -- --Guido van Rossum (python.org/~guido)