code: def open(self):
          
          self.device = serial.Serial(port=self.devfile, baudrate=self.baudrate, bytesize=self.bytesize, parity=serial.PARITY_NONE, stopbits=serial.STOPBITS_ONE, timeout=self.timeout, dsrdtr=True)
  
          if self.device is not None:
              print "Serial printer enabled"
          else:
              print "Unable to open serial printer on: %s" % self.devfile
docs: Setup serial port and set is as escpos device