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Extending attrs-generated `__eq__`

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Assessment

Difficulty
3/5
Estimated time
1-2 days
Newbie friendliness
42/100
Issue type
Feature
Clarity
Mostly clear
Activity status
Stale
Tech stack
python
Domain
developer-experience

Research direction

Start at attrs' generated eq entry point and compare it with the attrs_init extension path shown in the issue. Use the provided X and magic_object example to define the expected behavior, including preserving generated field comparisons while allowing custom equality logic.

Written by the indexing model from the issue text.

Description

Hi, I fear that there is probably a super obvious answer to this question, but I somehow cannot wrap my head around it: is there any way how I can "extend" the attrs-generated __eq__ method, similar to how it's possible for __init__ by calling __attrs_init__? 🤔

Here just a dummy example to illustrate the situation. Right now, the only way I can get it work is by writing the boilerplate myself.

from attrs import define

magic_object = object()
"""Is equal to all objects."""


@define
class X:
    here: int
    are: float
    many: str
    fields: bool

    def __eq__(self, other):
        if other is magic_object:
            return True
        
        # Ideally, I want to call something like:
        # return __attrs_eq__(other)

        # Instead, I have this boilerplate code!
        return (
            super().__eq__(other)
            and isinstance(other, X)
            and self.here == other.here
            and self.are == other.are
            and self.many == other.many
            and self.fields == other.fields
        )


assert X(0, 0.0, "a", True) == X(0, 0.0, "a", True)
assert X(0, 0.0, "a", True) != X(0, 0.0, "a", False)
assert X(0, 0.0, "a", True) == magic_object
Dominant language
Python
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Merged PRs (30d)
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