多态

多态：一种接口，多种实现

class Animal:
    def __init__(self, name):  # Constructor of the class
        self.name = name
    def talk(self):  # Abstract method, defined by convention only
        pass #raise NotImplementedError("Subclass must implement abstract method")
    #@staticmethod
    def animal_talk(obj):  #不需要调用self
        obj.talk()

class Cat(Animal):
    def talk(self):
        print('Meow!')


class Dog(Animal):
    def talk(self):
        print('Woof! Woof!')

c = Cat("haha")
d = Dog("hehe")
Animal.animal_talk(c)
Animal.animal_talk(d)