Python深入分析@property装饰器的应用

>>> class Goods():
        def __init__(self,unit_price,weight):
            self.unit_price = unit_price
            self.weight = weight
        @property
        def price(self):
            return self.unit_price * self.weight
>>> lemons = Goods(7,4)
>>>
>>> lemons.price
28

>>> class Lemons():
        def __init__(self,unit_price=7):
            self.unit_price = unit_price
        def get_unit_price(self):
            return self.unit_price
        def set_unit_price(self,new_unit_price):
            self.unit_price = new_unit_price
        def del_unit_price(self):
            del self.unit_price
        x = property(get_unit_price, set_unit_price, del_unit_price)
>>> fruit = Lemons()
>>> 
>>> fruit.x                         #调用 fruit.x 触发 get_unit_price
7
>>> 
>>> fruit.x = 9                     #调用 fruit.x = 9 触发 set_unit_price
>>> 
>>> fruit.x
9
>>> 
>>> fruit.unit_price                #调用 fruit.unit_price 触发 get_unit_price
9
>>> del fruit.x                     #调用 del fruit.x 触发 del_unit_price 
>>> 
>>> fruit.unit_price
Traceback (most recent call last):
  File "<pyshell#23>", line 1, in <module>
    l.unit_price
AttributeError: 'Lemons' object has no attribute 'unit_price'

class Person(object):
    pass
p = Person()
p.age = 1000

# -*- coding: utf-8 -*-
class Person(object):
    # score属性的值 限制范围为：0-88
    def get_age(self):
        return self.__age
    def set_age(self, value):
        if 0 <= value <= 88:
            self.__age = value
        else:
            self.__age = 0  # 给age一个初始值0
            raise ValueError('age的值必须在0-88之间')  # 自动抛异常
if __name__ == '__main__':
    p = Person()
    p.set_age(100)
    p.get_age()

# -*- coding: utf-8 -*-
class Person(object):
    # score属性的值 限制范围为：0-88
    @property  # 把 age 属性暴露出去
    def age(self):
        return self.__age
    @age.setter  # 当前 age 属性可以允许赋值
    def age(self, value):
        if 0 <= value <= 88:
            self.__age = value
        else:
            self.__age = 0  # 给age一个初始值0
            raise ValueError('age的值必须在0-88之间')  # 自动抛异常
    @property
    def name(self):
        self.__name = '张三'
        return self.__name
if __name__ == '__main__':
    p = Person()
    p.age = 18
    print(p.age)  # age属性可以读，可以写
    print(p.name)  # name 只读属性