Python类的高级函数详解

def __str__(self):
	return str_type

def __getattr__(self, key):
	print(something.….)

def __settattr__(self, key,value):
	self._dict_[key] = value

def __call__(self,*args,**kwargs):
	print( 'call will start')

#!/usr/bin/python3
# -*- coding: utf-8 -*-
# @Time     : 2021/8/15 18:22
# @Author   : InsaneLoafer
# @File     : object_func.py

class Test(object):

    def __str__(self):
        return 'this is a test class'

    def __getattr__(self, key):
        return '这个key：{}并不存在'.fORMat(key)

    def __setattr__(self, key, value):
        print(key, value)
        self.__dict__[key] = value
        print(self.__dict__)

    def __call__(self, *args, **kwargs):
        print('call will start')
        print(args, kwargs)

t = Test()
print(t)
print(t.a)  # 不存在的对象会直接打印出来，而不是报错
t.name = 'insane'
t(123, name='loafer')


"""实现链式操作"""
class Test2(object):
    def __init__(self, attr=''):
        self.__attr = attr

    def __call__(self, name):
        print('key is {}'.format(self.__attr))
        return name

    def __getattr__(self, key):
        if self.__attr:
            key = '{}.{}'.format(self.__attr, key)
        else:
            key = key
        print(key)
        return Test2(key)  # 递归操作

t2 = Test2()
print(t2.a.c('insane'))

this is a test class
这个key：a并不存在
name insane
{'name': 'insane'}
call will start
(123,) {'name': 'loafer'}
a
a.c
key is a.c
insane

Process finished with exit code 0