property在python2和python3中的区别

• 问题背景: 源于公司的原来的代码是python2开发的，后来改为python3开发，设计到的property的用法有点不一样
• 直接上代码

公司原来的python2的代码

class LineItem:    def __init__(self, description, weight, price):        self.description = description        self.__weight = weight        self.price = price    @property    def weight(self):        return self.__weight    @weight.setter    def set_weight(self, value):        if value > 0:            self.__weight = value        else:            raise ValueError('weight must be > 0')

运行代码

In [2]: l = LineItem('a', 3, 6)In [3]: l.weightOut[3]: 3In [4]: l.weight = 5In [5]: l.weightOut[5]: 5

这个代码在python2下面执行没有问题，但是在python3下面执行，会报错，在执行In [4]: l.weight = 5的时候报错

In [4]: l.weight = 5---------------------------------------------------------------------------AttributeError                            Traceback (most recent call last)<ipython-input-4-3c1df6104a5e> in <module>----> 1 l.weight = 5AttributeError: can't set attribute

• 解决方法

按理说，上面的那种写法不是很规范，无论是在python2还是python3的文档实例里面都不是这么写的，所以为了简便和不出错，我们统一使用下面的这种写法

class LineItem:    def __init__(self, description, weight, price):        self.description = description        self.__weight = weight        self.price = price    @property    def weight(self):        return self.__weight    @weight.setter    def weight(self, value):        if value > 0:            self.__weight = value        else:            raise ValueError('weight must be > 0')

主要区别在于这一行def weight(self, value):