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 Type
def process_any_subclass_type_of_A(cls: Type[A]):
pass
From The type of class objects :
Sometimes you want to talk about class objects that inherit from a given class. This can be spelled as
Type[C]
whereC
is a class. In other words, whenC
is the name of a class, usingC
to annotate an argument declares that the argument is an instance ofC
(or of a subclass ofC
), but usingType[C]
as an argument annotation declares that the argument is a class object deriving fromC
(orC
itself).