Communicate with an Arduino thought the serial port
/*READ*/
import serial
ser = serial.Serial('/dev/tty.usbserial', 9600)
while 1:
ser.readline()
'1 Hello world!\r\n'
'2 Hello world!\r\n'
'3 Hello world!\r\n'
/*WRITE*/
import serial # if you have not already done so
ser = serial.Serial('/dev/tty.usbserial', 9600)
ser.write('5')