Micael Jarniac <mic...@jarniac.com> added the comment:
I'm trying to think of an example, and what I've thought of so far is having a base dataclass that has a `__post_init__` method, and another dataclass that inherits from it and also has a `__post_init__` method. In that case, the subclass might need to call `super().__post_init__()` inside its own `__post_init__` method, because otherwise, that wouldn't get called automatically. Something along those lines: >>> from dataclasses import dataclass, field >>> >>> @dataclass ... class A: ... x: int ... y: int ... xy: int = field(init=False) ... ... def __post_init__(self) -> None: ... self.xy = self.x * self.y ... >>> @dataclass ... class B(A): ... m: int ... n: int ... mn: int = field(init=False) ... ... def __post_init__(self) -> None: ... super().__post_init__() ... self.mn = self.m * self.n ... >>> b = B(x=2, y=4, m=3, n=6) >>> b B(x=2, y=4, xy=8, m=3, n=6, mn=18) In this example, if not for the `super().__post_init__()` call inside B's `__post_init__`, we'd get an error `AttributeError: 'B' object has no attribute 'xy'`. I believe this could be an actual pattern that could be used when dealing with dataclasses. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue44365> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
