How do I correctly add type-hints to Mixin classes?

Question

Consider the following example. The example is contrived but illustrates the point in a runnable example:

class MultiplicatorMixin:

    def multiply(self, m: in         


        

Answer 1

I've tested it on my machine, hope it will also work for you:

class MultiplicatorMixin:
    value = None # type: int

    def multiply(self, m: int) -> int:
        return self.value * m


class AdditionMixin:
    value = None # type: int

    def add(self, b: int) -> int:
        return self.value + b


class MyClass(MultiplicatorMixin, AdditionMixin):

    def __init__(self, value: int) -> None:
        self.value = value


instance = MyClass(10)
print(instance.add(2))
print(instance.multiply(2))