class Chain(object):
    def __init__(self,path=''):
        self._path = path
    def __getattr__(self,path):
        return Chain('%s/%s'%(self._path,path))
    def __call__(self,username):
        return Chain('%s/%s'%(self._path,username))
    def __str__(self):
        return self._path
    __repr__ = __str__

print(Chain().list.user('hong').data)

