Class

from abc import ABCMeta, abstractclassmethod


class Pet(object, metaclass=ABCMeta):
    """ Pet Class"""

    def __init__(self, nickname):
        self._nickname = nickname


    @abstractclassmethod
    def make_sound(cls):
        """ Make a sound """
        pass


class Dog(Pet):
    """ Dog """

    def make_sound(self):
        print("Dog %s barks!" % self._nickname)


class Cat(Pet):
    """ Cat """

    def make_sound(self):
        print("Cat %s meows!" % self._nickname)


def main():
    pets = [Dog("Jack"), Cat("Tom")]
    for pet in pets:
        pet.make_sound()


if __name__ == "__main__":
    main()

Dog Jack barks!
Cat Tom meows!