python enums with attributes

Question

Consider:

class Item:
   def __init__(self, a, b):
       self.a = a
       self.b = b

class Items:
    GREEN = Item(\'a\', \'b\')
    BLUE = Item(\'c\', \'         


        

Answer 1

Python 3.4 has a new Enum data type (which has been backported as enum34 and enhanced as aenum¹). Both enum34 and aenum² easily support your use case:

[aenum py2/3]

import aenum
class EnumWithAttrs(aenum.AutoNumberEnum):
    _init_ = 'a b'
    GREEN = 'a', 'b'
    BLUE = 'c', 'd'

[enum34 py2/3 or stdlib enum 3.4+]

import enum
class EnumWithAttrs(enum.Enum):

    def __new__(cls, *args, **kwds):
        value = len(cls.__members__) + 1
        obj = object.__new__(cls)
        obj._value_ = value
        return obj

    def __init__(self, a, b):
        self.a = a
        self.b = b

    GREEN = 'a', 'b'
    BLUE = 'c', 'd'

And in use:

--> EnumWithAttrs.BLUE


--> EnumWithAttrs.BLUE.a
'c'

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¹ Disclosure: I am the author of the Python stdlib Enum, the enum34 backport, and the Advanced Enumeration (aenum) library.

² aenum also supports NamedConstants and metaclass-based NamedTuples.