python 类(1)

class Cat():    """  类 """    tag = ‘我是家猫‘    def __init__(self,name,age):        self.name = name        #  私有变量        self.__age = age    def set_age(self,age):        self.__age = age        # return self.__age    def show_info(self):       rest = ‘我叫:{0},今年{1}岁‘.format(self.name,self.__age)       print(rest)       return rest    def eat(self):        """ 吃 """        print("猫喜欢吃鱼")    def catch(self):        """  抓老鼠 """        print("我能抓老鼠")if __name__ == ‘__main__‘:    # 实例化    cat_black = Cat(‘小黑‘,2)    cat_black.eat()    cat_black.show_info()    print(‘--------‘)    # print(cat_black.name)  # 小黑    # print(cat_black.age)    #  私有变量无法访问    # print(cat_black.__age)    cat_black.name  = ‘小白‘    cat_black.show_info()  #我叫:小白,今年2岁    print(‘--------‘)    # 设置年龄    # cat_black.set_age(7)    # cat_black.show_info()  我叫:小白,今年7岁    print(Cat.tag)    print(cat_black.tag)    print(‘--------‘)    # 判断是否是类的实例    print(isinstance(cat_black,Cat))  #True