How to access class attributes of a derived class in the base class in Python3?

Question

I want to do something in a base class (FooBase) with the class attribues of the derived classes (Foo). I want to do this with Python3.

class BaseFoo:
   #felder = [] doesn't work

   def test():
      print(__class__.felder)

class Foo(BaseFoo):
   felder = ['eins', 'zwei', 'yep']


if __name__ ==  '__main__':
    Foo.test()

Maybe there is a different approach to this?

Answer 1

You need to make test a class method, and give it an argument that it can use to access the class; conventionally this arg is named cls.

class BaseFoo:
    @classmethod
    def test(cls):
        print(cls.felder)

class Foo(BaseFoo):
    felder = ['eins', 'zwei', 'yep']


if __name__ ==  '__main__':
    Foo.test()

output

['eins', 'zwei', 'yep']