Python3 getattr, getattrubute 区别和应用场景-昊天SEO

# -*- coding: utf-8 -*-
"""
@Time: 2018/4/30
@Author: songhao
@微信公众号: zeropython
@File: demo_getattr.py
"""
"""
getattr, getattrubute
getattr 在查找不到属性的时候调用
class User:
    def __init__(self,name):
        self.name =name

    def __getattr__(self, item):
        return ("not find atter")


if __name__ == '__main__':
    user= User("songhao")
    print(user.age)
    print(user.name)
输出结果
# not find atter
# songhao

class User:
    def __init__(self, name, info={}):
        self.name = name
        self.info = info

    def __getattr__(self, item):
        return self.info[item]


if __name__ == '__main__':
    user = User("songhao",info={"weixin":"zeropython"})
    print(user.weixin)

输出：
# zeropython

class User:
    def __init__(self, name, info={}):
        self.name = name
        self.info = info

    def __getattr__(self, item):
        return self.info[item]

    def __getattribute__(self, item):
       # 调用属性最优先调用这个属性
        return "hello world"


if __name__ == '__main__':
    user = User("songhao",info={"weixin":"zeropython"})
    print(user.weixin)

输出：
#hello world

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

"""

@Time: 2018/4/30

@Author: songhao

@微信公众号: zeropython

@File: demo_getattr.py

"""

getattr, getattrubute

getattr 在查找不到属性的时候调用

class User:

def __init__(self,name):

self.name =name

def __getattr__(self, item):

return ("not find atter")

if __name__ == '__main__':

user= User("songhao")

print(user.age)

print(user.name)

输出结果

# not find atter

# songhao

class User:

def __init__(self, name, info={}):

self.name = name

self.info = info

def __getattr__(self, item):

return self.info[item]

if __name__ == '__main__':

user = User("songhao",info={"weixin":"zeropython"})

print(user.weixin)

输出：

# zeropython

class User:

def __init__(self, name, info={}):

self.name = name

self.info = info

def __getattr__(self, item):

return self.info[item]

def __getattribute__(self, item):

# 调用属性最优先调用这个属性

return "hello world"

if __name__ == '__main__':

user = User("songhao",info={"weixin":"zeropython"})

print(user.weixin)

输出：

#hello world

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

class Student(object):

    def __init__(self):
        self.name = 'Michael'

    def __getattr__(self, attr):
        if attr=='score':
            return 99
        if attr=='age':
            return lambda: 25
        raise AttributeError('\'Student\' object has no attribute \'%s\'' % attr)

s = Student()
print(s.name)
print(s.score)
print(s.age())
# AttributeError: 'Student' object has no attribute 'grade'
print(s.grade)