Subclass in type hinting
When you specify cls: A, you're saying that cls expects an instance of type A. The type hint to specify cls as a class object for the type A (or its subtypes) uses typing.Type.
from typing import Typedef process_any_subclass_type_of_A(cls: Type[A]): passFrom The type of class objects:
Sometimes you want to talk about class objects that inherit from agiven class. This can be spelled as
Type[C]whereCis a class. Inother words, whenCis the name of a class, usingCto annotate anargument declares that the argument is an instance ofC(or of asubclass ofC), but usingType[C]as an argument annotation declaresthat the argument is a class object deriving fromC(orCitself).