def from_url(self, url):
        """extract host and port from an URL string"""
        parts = urlparse.urlsplit(url)
        if parts.scheme != 'spy':
            raise serial.SerialException(
                'expected a string in the form '
                '"spy://port[?option[=value][&option[=value]]]": '
                'not starting with spy:// (%r)' % (parts.scheme,))
        # process options now, directly altering self
        formatter = FormatHexdump
        color = False
        output = sys.stderr
        try:
            for option, values in urlparse.parse_qs(parts.query, True).items():
                if option == 'file':
                    output = open(values[0], 'w')
                elif option == 'color':
                    color = True
                elif option == 'raw':
                    formatter = FormatRaw
                elif option == 'all':
                    self.show_all = True
                else:
                    raise ValueError('unknown option: %r' % (option,))
        except __HOLE__ as e:
            raise serial.SerialException(
                'expected a string in the form '
                '"spy://port[?option[=value][&option[=value]]]": %s' % e)
        self.formatter = formatter(output, color)
        return ''.join([parts.netloc, parts.path])
dataset/ETHPy150Open pyserial/pyserial/serial/urlhandler/protocol_spy.py/Serial.from_url