python中类的多态和继承

# -*- coding: utf-8 -*-

class Animal:

    def eat(self):
        print('Animal is eating...')


class Bird(Animal):

    def sing(self):
        print('Brids is singing...')

    def eat(self):
        print('Brid is eating...')


class Dog(Animal):

    def laugh(self):
        print('Dogs is laughing...')

    #def eat(self):
        #print('Dog is eating...')
        pass


a = Animal()
# a.eat()
#
b = Bird()
# b.eat()
# b.sing()
#
d = Dog()
# d.eat()
# d.laugh()


def demo_eat(q):
    q.eat()


for iteam in [a, b, d]:
    demo_eat(iteam)