python __str__方法

class Cat:

    def __init__(self, new_name):

        self.name = new_name

        print("%s 来了" % self.name)

    def __del__(self):

        print("%s 我去了" % self.name)

    def __str__(self):

        # 必须返回一个字符串
        return "我是小猫[%s]" % self.name

# tom 是一个全局变量
tom = Cat("Tom")
print(tom)

class Person:

    def __init__(self, name, weight):

        # self.属性 = 形参
        self.name = name
        self.weight = weight

    def __str__(self):

        return "我的名字叫 %s 体重是 %.2f 公斤" % (self.name, self.weight)

    def run(self):
        print("%s 爱跑步，跑步锻炼身体" % self.name)

        self.weight -= 0.5

    def eat(self):
        print("%s 是吃货，吃完这顿再减肥" % self.name)

        self.weight += 1

xiaoming = Person("小明", 75.0)

xiaoming.run()
xiaoming.eat()

print(xiaoming)

class Person:

    def __init__(self, name, weight):

        # self.属性 = 形参
        self.name = name
        self.weight = weight

    def __str__(self):

        return "我的名字叫 %s 体重是 %.2f 公斤" % (self.name, self.weight)

    def run(self):
        print("%s 爱跑步，跑步锻炼身体" % self.name)

        self.weight -= 0.5

    def eat(self):
        print("%s 是吃货，吃完这顿再减肥" % self.name)

        self.weight += 1

xiaoming = Person("小明", 75.0)

xiaoming.run()
xiaoming.eat()

print(xiaoming)

# 小美爱跑步
xiaomei = Person("小美", 45)

xiaomei.eat()
xiaomei.run()

print(xiaomei)
print(xiaoming)