Dog和Cat都繼承Animal，都使用父類的init方法，但是greet方法卻是不同的，子類對(duì)父類進(jìn)行了覆蓋，還編寫了自己的run方法

class Animal(object):
    def __init__(self,name):
        self.name = name
    def greet(self):
        print('I am a animal')

class Dog(Animal):
    def greet(self):
        print('I am a ' + self.name + ' dog')
    def run(self):
        print('dog run')

class Cat(Animal):
    def greet(self):
        print('I am a ' + self.name + ' cat')
    def run(self):
        print('cat run')


dog = Dog('black')
cat = Cat('white')
dog.greet()
cat.greet()
dog.run()
cat.run()
# isinstance判斷某個(gè)數(shù)據(jù)是否是該類型
print(isinstance(dog,Animal))
print(isinstance(cat,Animal))
print(isinstance(dog,Dog))
print(isinstance(dog,Cat))