copy_enum_members

The copy_enum_members() class decorator is used to loosely inherit from an existing Enum. The defined members in the base class(es) will be copied to the derived class, creating a completely distinct Enum, but allowing reuse of already defined member names/values.

Decorating a Class with copy_enum_members

The copy_enum_member decorator can only be applied to classes with the EnumMeta metaclass. The decorator takes a variable number of arguments, each of which must be an Enum, otherwise a TypeError will be raised. The derived class can also define new members:

from enum import Enum
from extendableenum import copy_enum_members

class Fruits(Enum):
APPLE = 1
BANANA = 2
PEAR = 3

class Vegetables(Enum):
    ASPARAGUS = 11
    BROCCOLI = 12
    CARROT = 13

@copy_enum_members(Fruits, Vegetables)
class MyFavoriteFoods(Enum):
    BEEF = 21
    CHICKEN = 22
    PORK = 23

MyFavoriteFoods.APPLE
MyFavoriteFoods.BROCCOLI is not Vegetables.BROCCOLI

>>> MyFavoriteFoods.APPLE
>>> True

Note

It is the user’s responsibility to ensure that names of the copied members do not conflict, otherwise a TypeError will be raised.

Note

If a duplicated member has the same value as a previously defined member, the member will become an alias in the new Enum. Priority is based on the order of the arguments supplied to the decorator function. Members defined in the new Enum have the lowest priority.

The __copied_from__ Attribute

The copy_enum_members decorator adds the __copied_from__ attribute to the decorated Enum, which is simply the arguments that were passed to the decorator.

MyFavoriteFoods.__copied_from__

>>> (<enum 'Fruits'>, <enum 'Vegetables'>)