property初识

Posted 2021-01-31 eric818

1、为什么要用property属性？

答：用property属性可以很方便的取值和设值，以前都是用方法来实现的，用方法的话还得考虑参数等等，不方便。

2、如何设置property属性？

答：有两种方法：

1>利用装饰器：

 1 class Food(object):
 2     def __init__(self):
 3         self.old_price = 100
 4         self.discount = 0.8
 5 
 6     @property
 7     def price(self):
 8         new_price = self.old_price * self.discount
 9         return new_price
10 
11     @price.setter
12     def price(self, value):
13         self.old_price = value
14 
15     @price.deleter
16     def price(self):
17         del self.old_price
18 
19 obj = Food()
20 obj.price
21 obj.price = 200
22 del obj.price

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2>利用类属性：

 1 class Food(object):
 2     def __init__(self):
 3         self.old_price = 100
 4         self.discount = 0.8
 5 
 6     def get_price(self):
 7         new_price = self.old_price * self.discount
 8         return new_price
 9 
10     def set_price(self, value):
11         self.old_price = value
12 
13     def del_price(self):
14         def self.old_price
15 
16     
17         
18 
19      PRICE = property(get_price, set_price, del_price, "description...")
20 
21 obj = Food()
22 obj.price
23 obj.price = 200
24 del obj.price

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