用户登陆
        :return: true if login successfully

def login(self):
        """
        用户登陆
        :return: true if login successfully
        """
        self._cookies = self.__get_rndnum_cookies()
        # print self._cookies
        UserCode, UserPwd = self._userid, self._userpsw
        Validate = self._cookies['LogonNumber']
        Submit = '%CC%E1+%BD%BB'
        headers = {'Referer': 'http://jwc.wyu.edu.cn/student/body.htm'}
        # save header
        self._headers = headers
        data = {
            'UserCode': UserCode,
            'UserPwd': UserPwd,
            'Validate': Validate,
            'Submit': Submit,

        }
        r = requests.post('http://jwc.wyu.edu.cn/student/logon.asp', data=data, headers=headers, cookies=self._cookies)
        # print r.content.decode(_.get_charset(r.content))
        return True if r.status_code == 200 else False