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__ne__ does not defer to custom __eq__ #585
Description
Description
I've encountered unexpected behavior with custom-defined __eq__ methods:
class A(msgspec.Struct, eq=False):
x: int
y: int
def __eq__(self, other):
return self.__class__ == other.__class__ and self.x == other.x
x = A(1, 2)
y = A(1, 3)
print(x == y) # True
print(x != y) # True <-- unexpected!The default implementation of __ne__ just defers to __eq__, so x != y should be False. It seems that Struct has its own __ne__ implementation that does not do this.
Admittedly, this is a really weird case that would probably be solved by making y a private field (#199). I'd also be happy with just updating the docs to state that if you provide a custom __eq__ that you should also define __ne__.
Activity
jcrist commentedon Nov 25, 2023
Thanks for the excellent reproducible issue, this has been fixed in #593.
As part of that work I also intend to support field level configuration for
eq/repr/init, matching the behavior of dataclasses and attrs. When that's done, you should be able to do something like this to get what you want:Solumin commentedon Nov 25, 2023
Thank you for fixing this so quickly!
Excellent, I think that will be a very helpful feature.