Accessing super(parent) class variable in python

Question

I am new to python. Im trying to access the parent class variable in child class using super() method but it throws error "no arguments". Accessing class variable using class name works but i like to know whether it is possible to access them using super() method.

class Parent(object):
        __props__ = (
            ('a', str, 'a var'),
            ('b', int, 'b var')
        )

        def __init__(self):
            self.test = 'foo'

class Child(Parent):
    __props__ = super().__props__ + (
        ('c', str, 'foo'),
    ) # Parent.__props__


    def __init__(self):
        super().__init__()

Error:

    __props__ = super().__props__ + (
RuntimeError: super(): no arguments

Answer 1

You could define an __init_subclass__ method of the Parent class that initializes Child.__props__. This method is called every time a subclass of of Parent is created, and we can use it to modify the __props__ that class inherits with an optional __props__ argument passed as part of the class definition.

class Parent:
    __props__ = (('a', str, 'a var'), ('b', int, 'b var'))
    def __init_subclass__(cls, __props__=(), **kwargs):
        super().__init_subclass__(**kwargs)
        cls.__props__ = cls.__props__ + __props__

class Child(Parent, __props__=(('c', str, 'foo'),)):
    pass

print(Child.__props__)
# (('a', <class 'str'>, 'a var'), ('b', <class 'int'>, 'b var'), ('c', <class 'str'>, 'foo'))

class GrandChild(Child, __props__=(('d', float, 'd var'),)):
    pass

print(GrandChild.__props__)
# (('a', <class 'str'>, 'a var'), ('b', <class 'int'>, 'b var'), 
#  ('c', <class 'str'>, 'foo'), ('d', <class 'float'>, 'd var'))