class Parent1:
    def __init__(self):
        print("Parent1.__init__")
        super().__init__()

class Parent2:
    def __init__(self):
        print("Parent2.__init__")
        super().__init__()

class Child(Parent1, Parent2):
    def __init__(self):
        print("Child.__init__")
        super().__init__()

if __name__ == '__main__':
    print(Child.__mro__)
    Child()

# Output:
#   (<class '__main__.Child'>, <class '__main__.Parent1'>, <class '__main__.Parent2'>, <class 'object'>)
#   Child.__init__
#   Parent1.__init__
#   Parent2.__init__