'parse UPnP error message, err_resp is the returned XML in http body
reurn UPnP error code and error description'

def _parseErrMsg(self, err_resp):

    dom = fromstring(err_resp)
    err_code = dom.find('.//control:errorCode', self.NS)
    err_desc = dom.find('.//control:errorDescription', self.NS)
    return (err_code.text, err_desc.text)
