5 属性 property

1.属性  property

　调用私有属性通过实例方法调用。达到这种效果

#property的作用:相当于把方法进行了封装, 开发者在对属性设置数据的时候更方便

class Dog(object):

    def __init__(self):

        self.__num = 100

    def set_num(self,new_num):

        print("---setter")

        self.__num = new_num

    def get_num(self):

        print("----getter--")

        return self.__num

    num = property(get_num,set_num)    #通过属性实现这种效果

dog1 = Dog()

#print(dog1.get_num())

#dog1.set_num(50)

#print(dog1.get_num())

print("-"*50)

dog1.num = 111   #相当于调用了dog1.set_num(200)

print(dog1.num)   #相当于调用了dog1.get_num()

####  运行结果

---setter

----getter--

111

#注意点:

#t.num 到底是调用getNum()还是setNum(),要根据实际的场景来判断,

#1. 如果是给t.num赋值 那么一定调用setNum()

#2. 如果是获取t.num的值,那么就一定调用getNum()

2.@property

class Dog(object):

    def __init__(self):

        self.__num = 100

    @property

    def to_num(self):       #同名函数

        print("---getter")

        return self.__num

    @to_num.setter    #函数名.setter

    def to_num(self,new_num):  #同名函数

        print("---setter")

        self.__num = new_num

   # num = property(get_num,set_num)

dog1 = Dog()

dog1.to_num = 111   #相当于调用to_num(111)

print(dog1.to_num)   #相当于调用to_num()

---setter

---getter

111