Example from PEP0435:

(https://www.python.org/dev/peps/pep-0435)

>>> from enum import Enum
>>> class Color(Enum):
...     red = 1
...     green = 2
...     blue = 3

Example from Python documentation:

(https://docs.python.org/3/library/enum.html)

>>> from enum import Enum
>>> class Color(Enum):
...     RED = 1
...     GREEN = 2
...     BLUE = 3
...

So, what are the rules for naming enum members?
CamelCase ? snake_case ? ALL_CAPS ?

Someone should explain how should we format sources. So various linters may check for that.