28 – Flag enumerations

The module enum contains a type Flag that you can use for enumerations that should support the Boolean operations & (AND), | (OR), ^ (XOR), and ~ (INVERT):

from enum import Flag, auto

class Color(Flag):
    RED = auto()
    GREEN = auto()
    BLUE = auto()

# Purple is red with blue:
purple = Color.RED | Color.BLUE

Flag enumerations also support other useful operations, like containment check:

# Is the flag GREEN set?
print(Color.GREEN in purple)  # False

In Python 3.11+, you can also get a list of the individual flags that are set:

# What flags is `purple` composed of?
print(list(purple))  # [<Color.RED: 1>, <Color.BLUE: 4>]