多态实例

class Animal:
    def __init__(self, name):    # Constructor of the class
        self.name = name

    def talk(self):              # Abstract method, defined by convention only
        #只要你调用我就报错
        raise NotImplementedError("Subclass must implement abstract method")

class Cat(Animal):
    def talk(self):
        return ‘Meow!‘
class Dog(Animal):
    def talk(self):
        return ‘Woof! Woof!‘
d = Dog("d1")
c = Cat("C1")
# Animal.talk(d)
# Animal.talk(c)
def animal_talk(obj):
    print(obj.talk())
animal_talk(d)
animal_talk(c)