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singledispatchmethod.register fails with typing.Self annotation #130827
Description
Bug report
Bug description:
When using singledispatchmethod, the register decorator function raises an exception if self is annotated with typing.Self:
TypeError: Invalid annotation for 'self'. typing.Self is not a class.
Minimal example:
from functools import singledispatchmethod
from typing import Self
class Foo:
@singledispatchmethod
def bar(self: Self, arg: int | str) -> int | str: ...
@bar.register
def _(self: Self, arg: int) -> int:
return arg
foo = Foo()
print(foo.bar(1))The workaround is to remove the typing.Self annotation for the _ function.
(Same for singledispatch but that should not be used in that case anyway)
CPython versions tested on:
3.13
Operating systems tested on:
Linux
Activity
ZeroIntensity commentedon Mar 4, 2025
Presumably, we want to:
Selfonsingledispatch.singledispatchmethod.That seems easy enough, but we'll probably need a new internal helper to hide any talking between
singledispatchandsingledispatchmethod. I'll submit a fix.pythongh-130827: Support typing.Self in singledispatchmethod()
Add pythonGH-130827 test
Merge pythonGH-130827 test into `test_method_type_ann_register`