class Animal:
    pass


class Dog(Animal):
    pass


class Cat(Animal):
    pass


def func1():
    dog = Dog()
    animal = Animal()
    if isinstance(dog, Dog):
        print('dog obj is an instance of Dog')
    if isinstance(dog, Animal):
        print('dog obj is an instance of Animal')
    if isinstance(animal, Animal):
        print('animal obj is an instance of Animal')


def func2():
    dog = Dog()
    cat = Cat()
    if isinstance(dog, (Dog, Cat)):
        print('ok dog')
    if isinstance(cat, (Dog, Cat)):
        print('ok cat')


def func3():
    if isinstance("456", str):
        print("ok 1")
    if isinstance(456, int):
        print('ok 2')


if __name__ == '__main__':
    # isinstance:判断一个对象是不是某个类的实例
    func1()
    # isinstance:判断一个对象是不是某些类的实例
    func2()
    # isinstance:检查对象是否属于某个数据类型
    func3()