class SerialPort(serialport.SerialPort):

    def _serialFactory(self, dev, *args, **kwargs):
        """ pyserial recommends the following for supporting serial urls """
try:
    return serial.serial_for_url(dev)
except AttributeError:
    return serial.Serial(dev, *args, **kwargs)
Использовать сетевые последовательные порты RFC2217 с Twisted Python?