animals.py

class Animal:
    def __init__(self, name, species):
        self.name = name
        self.species = species

    def speak(self):
        return 'blah blah'


class Dog(Animal):
    def __init__(self, name, species, color):
        super().__init__(name, species)
        self.color = color

    def speak(self):
        return 'bow bow'


class Cat(Animal):
    def __init__(self, name, species, color):
        super().__init__(name, species)

    def speak(self):
        return 'meow meow'

snow = Dog('snow', 'mammal', 'white')
oscar = Cat('oscar', 'mammal)

print(snow.speak)
print(oscar.speak)