Python property使用简介

功能简介

1） 把类方法变成只读属性

2） setter和getter的另一种实现

代码演示1

#!/usr/bin/env python

# -*- coding:utf-8 -*-

__author__ = 'shouke'

class User(object):

def __init__(self, username, password):

self._username = username

self._password = password

@property

def username(self):

return self._username

@username.setter

def username(self, username):

self._username = username

@property

def password(self):

return self._password

@password.setter

def password(self, password):

self._password = password

if __name__ == '__main__':

boy = User('shouke', 'shouke2014')

print('对象用户名:', boy.username)

boy.username = 'shou ke'

print('修改后的用户名:', boy.username)

print('通过修改属性值来修改密码')

boy._password = 2014

print('修改后的用户密码:', boy._password)

boy.password = 'shouke2016'

print('通过方法属性来修改密码，修改后的用户密码:', boy._password)

运行结果：

对象用户名: shouke

修改后的用户名: shou ke

通过修改属性值来修改密码

修改后的用户密码: 2014

通过方法属性来修改密码，修改后的用户密码: shouke2016

注意：

1、@property和@function.setter需要成对使用，如下

@property

def function_name

@function.setter

def function_name(self, attribute)

2、如果变量属性值和方法属性值相同，那么以下情况下是无法完成初始化函数 __init__ 中的赋值操作的，即无法初始化对象

代码演示2

#!/usr/bin/env python # -*- coding:utf-8 -*- __author__ = 'shouke' class Tester(object): def __init__(self, name, sex, title): self.name = name self.sex = sex self.title = title @property def name(self): return self.name @property def sex(self): return self.sex @property def title(self): return self.title @title.setter def title(self, title): self.title = title if __name__ == '__main__': tester = Tester('shouke', 'M', 'Tester') print(tester.title)

"D:\Program Files\python33\python.exe" E:/Projects/untitled/py1.py

Traceback (most recent call last):

File "E:/Projects/untitled/py1.py", line 30, in

tester = Tester('shouke', 'M', 'Tester')

File "E:/Projects/untitled/py1.py", line 8, in __init__

self.name = name

AttributeError: can't set attribute