x.py

class A:
    def __init__(self):
        self.__c = 1

    def a(self):
        self.__c += 1

    def show(self):
        print(f"{self=} a.c is {self.__c=}")

class B(A):
    def __init__(self):
        super().__init__()
        self.__c = 10

    def b(self):
        self.__c += 10

    def show(self):
        super().show()
        print(f"{self=} b.c is {self.__c=}")
              

b = B()
b.show()
b.b()
b.b()
b.a()
print()
b.show()