[Python-ideas] Re: Make dataclass aware that it might be used with Enum

July 7, 2022


      Steve Jorgensen wrote:
...
Perhaps, this has already been addressed in a newer release (?) but in Python 3.9, making `@dataclass` work with `Enum` is a bit awkward.
Currently, it order to make it work, I have to:
1. Pass `init=False` to `@dataclass` and hand-write the `__init__` method
2. Pass `repr=False` to `@dataclass` and use `Enum`'s representation or write a custom __repr__
Example:
In [72]: @dataclass(frozen=True, init=False, repr=False)
    ...: class Creature(Enum):
    ...:     legs: int
    ...:     size: str
    ...:     Beetle = (6, 'small')
    ...:     Dog = (4, 'medium')
    ...:     def __init__(self, legs, size):
    ...:         self.legs = legs
    ...:         self.size = size
    ...:
In [73]: Creature.Dog
Out[73]: <Creature.Dog: (4, 'medium')>
Actually, maybe these are fundamentally incompatible? `@dataclass` is a decorator, so it acts on the class after it was already defined, but `Enum` acts before that when `@dataclass` cannot have not generated the `__init__` yet. Right?