Kumar Ayush

The short answer is that enums derive their unique value by restricting a variable's values in a program. This is contradictory to Python's type system. Thus, Python enums are an elephant's tusks.

In my practical life, there are two situations where I have felt a need for an Enum in Python.

1. I might want to restrict the possible values of a column. An enum is useless here because it is not a valid dtype. You are encouraged to use a pandas.Categorical to achieve this. That's not the same as an enum, because np.nan is intrinsically supported as a valid value.
2. I want to restrict the values of a function argument. There are no ways for the interpreter to do this, but static type checkers do this. But why would I instead not use typing.Literal for this purpose?

I have found it convenient to define a Literal type that can be re-used across my codebase.

from typing import Literal

Fruit = Literal['apple', 'orange']

See Also

• Enums with SqlAlchemy
• Behaviour quirk of Enum and IntEnum

>>> from enum import Enum, IntEnum
>>> class Fruit(IntEnum):
...     Apple = 1
...     Orange = 2
... 
>>> fruit = Fruit.Apple
>>> fruit == 1
True
>>> class Fruit(Enum):
...     Apple = 1
...     Orange = 2
... 
>>> fruit = Fruit.Apple
>>> fruit == 1
False

Thus, even if you must, use an IntEnum.