ArgumentParser.parse_args with Namespace subclass does not work anymore

[lkct]

Ref: microsoft/pylance-release#4569 (comment)

This is introduced in #10307. (cc @qthequartermasterman as the author)

typeshed/stdlib/argparse.pyi

Lines 173 to 178 in 31dca1d

	@overload
	def parse_args(self, args: Sequence[str] | None = None, namespace: Namespace | None = None) -> Namespace: ... # type: ignore[misc]
	@overload
	def parse_args(self, args: Sequence[str] | None, namespace: _N) -> _N: ...
	@overload
	def parse_args(self, *, namespace: _N) -> _N: ...

The first overload now shadows the following. E.g., ArgumentParser().parse_args(namespace=MyNamespace()) should match the third but actually matches the first, which unexpectedly returns Namespace instead of MyNamespace.

[srittau]

See discussion in #10387.