How to Inherit Attributes in Python

Why does it print 0 and not 24?
Also, why does it bring up an error if I dont explicitly define num in the System class even though im doing it in the constructor?

from abc import ABC, abstractmethod
class System(ABC):

    num = 0

    def __init__(self, input):
        self.num = input
        return

    @abstractmethod
    def getNum(self):
        pass

class FirstSystem(System):
    def __init__(self, input):
        super().__init__(input)
        return

    def getNum(self):
        return super().num

foo = FirstSystem(24)
print(foo.getNum())

>Solution :

Try changing

def getNum(self):
    return super().num

to

def getNum(self):
    return self.num

and see if that helps 🙂