在python的父类函数中使用子类的类级别属性

Question

How can I change the respective class level attributes using the function of the base class without overloading the function?

class A:
    a = 0

    def addOne(self):
        print(A.a)      # prints 0
        A.a = A.a + 1
        print(A.a)      # it stores the value of a over all the child classes

class B(A):
    a = 0
    print(A.a)      # prints 0
    print(B.a)      # prints 0
    self.addOne()
    print(A.a)      # prints 1
    print(B.a)      # prints 0

Class C(A):
    a = 0
    print(A.a)      # prints 1
    print(C.a)      # prints 0
    self.addOne()
    print(A.a)      # prints 2
    print(C.a)      # prints 0

I want Ba = 1 and Ca = 1 after self.addOne() .

I don't want to use instance attributes as I will have to overload the addOne function for all the child classes.

Answer 1

Option 1: Use the type function to get the class of self .

def addOne(self):
    cls = type(self)
    cls.a += 1

Option 2: Turn addOne into a classmethod :

@classmethod
def addOne(cls):
    cls.a += 1