Python 类的高级函数(双下横线)

def __str__(self):
	return str_type

def __gatattr__(self, key):
	print(something...)

# coding:utf-8

class Test(object):

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

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


t = Test()
print(t)
# print(t.a)
print(t.a)
print(t.b)

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

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

# coding:utf-8

class Test(object):

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

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

    def __setattr__(self, key, value):
        # print(key, value)
        # if key not in self.__dict__:
        self.__dict__[key] = value
        print(self.__dict__)

    def __call__(self, a):
        print('call func will start')
        print(a)


t = Test()
print(t)
# print(t.a)
print(t.a)
print(t.b)
t.name = '小慕'
print(t.name)
t('dewei')
# t.a.b.c 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)


t2 = Test2()
name = t2.a.b.c('dewei')
print(name)


result = t2.name.age.sex('ok')
print(result)