Python enum classes

quick_enums.py

# Author: Anthony Wu

# A quick way to make Python enum classes.
# Uses range/enumerate to quickly generate a list of enumerated values,
# but only safe/useful for your application logic where you don't have
# to persist these values to a data store.

# Example A: hard code enum classes

class Fruits(object):
    (Apple,
     Orange,
     Pear,
     Strawberry,
     ) = range(1,5)

print Fruits.Apple # 1
print Fruits.Orange # 2
print Fruits.Pear # 3
print Fruits.Strawberry # 4


# Example B: a helper function that returns an enum class

def make_enum_class(*enum_names):
    class E(object):
        _human = {}
        @classmethod
        def humanize(cls, value):
            return cls._human.get(value, "[Undefined]")
    for i, n in enumerate(enum_names, 1):
        setattr(E, n, i)
        E._human[i] = n
    return E

MagicFruits = make_enum_class(
        "Apple",
        "Orange",
        "Pear",
        "Strawberry"
        )

for e in (MagicFruits.Apple, MagicFruits.Orange, MagicFruits.Pear, MagicFruits.Strawberry):
    print "%d --> %s" % (e, MagicFruits.humanize(e))