class Animal(object):
    def run(self):
        print('Animal is running...')

    def jump(self):
        print('Animal is jumpping....')

    def __run(self):
        print('I am a private method.')

class Dog(Animal):
    def run(self):
        print('Dog is running...')

class Cat(Animal):
    def run(self):
        print('Cat is running...')

dog = Dog()
print('实例化Dog类')
dog.run()

cat = Cat()
print('实例化Cat类')
cat.run()