Accessing Private Methods from a Protocol

[max-muoto]

Perhaps this is the intended functionality, but noticed that you aren't able to use a private method through self annotated with a protocol, take this example:

from typing import Protocol


class MyClass1(Protocol):
    def _private_meth(self) -> None: ...


class MyClass2:
    def public_meth(self: MyClass1) -> None:
        return self._private_meth()

Pyright Playground

From my point of view, in cases where self is being annotated with a protocol (such as in the cases of mixin, for which it's a common strategy) it would be able to make sense to access private methods without running into warnings, but perhaps there is a reason why this is the case.

[erictraut]

Pyright is working as intended here, so I don't consider this a bug.

To get the effect that you're looking for, MyClass2 should explicitly subclass from the protocol class.

class MyClass2(MyClass1):
    def public_meth(self) -> None:
        return self._private_meth()