Can I Use __qualname__ In A Python Type Hint With Postponed Annotation Evaluation?

I like using __qualname__ for the return-type annotation of factory-style class methods, because it doesn't hardcode the classname and therefore keeps working subclasses (cf. this

Solution 1:

Foo.make doesn't always return an instance of Foo (which is what __qualname__ expands to). It returns an instance of the class it receives as an argument, which isn't necessarily Foo. Consider:

>>>classFoo:...    @classmethod...defmake(cls):...return cls()...>>>classBar(Foo):...pass...>>>type(Bar.make())
<class '__main__.Bar'>

The correct type hint would be a type variable:

T = TypeVar("T", bound="Foo")

classFoo:@classmethoddefmake(cls: Type[T]) -> T:return cls()