Annotate subclass's method?

Suppose I have a Mixin class Mixin, and a method a in this class uses another method
b which will be in another Base class. I want to annotate b in class Mixin so that I can take the advantages of inspection.

Mixin

a

b

Base

b

Mixin

The real usage is multiple inherition. I create a mixin for tornado.web.RequestHandler, and the subclass could inherit both RequestHandler and Mixin to get some useful functions.

tornado.web.RequestHandler

RequestHandler

Mixin

As far as I know, I can annotate b as Callable, but I cannot annotate its signature.

b

Callable

class Base

def b():
# do something

class Mixin:
b: Callable # not enough, losing signature.
#b: RequestHandler.b # not work, still losing signature.
def a():
# call b here.

class subclass(Base, Mixin):
pass


BTW, I'm using Pycharm.

Are you trying to annotate the subclass method or attribute?
– Ramazan Polat
Jun 29 at 9:02

@RamazanPolat It isn't related to subclass but only baseclass. I need to use function b in function a, and I hope pycharm can inspect b's signature while I am writing a.
– Sraw
Jun 29 at 9:06

b

a

b

a

AFAIU, in Base class, a method named A will call another method called B. The method B will be defined in a subclass of Base. Is this correct?
– Ramazan Polat
2 days ago

Do you mean that b in subclasses could have different signatures or they are always same?
– user2235698
2 days ago

b

Guys, see my update. Sorry for confusion.
– Sraw
2 days ago

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