#-*- coding:utf-8 -*-def trima(s):    if s[0:1] != ' ':        return s    else:        s = s[1:]        return trima(s)def trimz(s):    if s[-1:] != ' ':        return s    else:        s = s[:-1]        return trimz(s)def trim(s):    s = trimz(trima(s))    return s