'extract host and port from an URL string'

def from_url(self, url):

    parts = urlparse.urlsplit(url)
    if (parts.scheme != 'loop'):
        raise SerialException('expected    a    string    in    the    form    "loop://[?logging={debug|info|warning|error}]":    not    starting    with    loop://    ({!r})'.format(parts.scheme))
    try:
        for (option, values) in urlparse.parse_qs(parts.query, True).items():
            if (option == 'logging'):
                logging.basicConfig()
                self.logger = logging.getLogger('pySerial.loop')
                self.logger.setLevel(LOGGER_LEVELS[values[0]])
                self.logger.debug('enabled    logging')
            else:
                raise ValueError('unknown    option:    {!r}'.format(option))
    except ValueError as e:
        raise SerialException('expected    a    string    in    the    form    "loop://[?logging={debug|info|warning|error}]":    {}'.format(e))
