Programmatically talking to a Serial Port in OS X or Linux

stty -f /dev/cu.usbserial
speed 9600 baud;
lflags: -icanon -isig -iexten -echo
iflags: -icrnl -ixon -ixany -imaxbel -brkint
oflags: -opost -onlcr -oxtabs
cflags: cs8 -parenb

#!/usr/bin/python

import serial

ser = serial.Serial('/dev/cu.usbserial', 9600, timeout=10)
ser.write("<ID01><PA> rn")
read_chars = ser.read(20)
print read_chars

ser.close()

/dev/cu.usbserial-xxxxxxxxA/dev/tty.usbserial-xxxxxxxxA/dev/cu.usbserial-xxxxxxxxB/dev/tty.usbserial-xxxxxxxxB