Pyton serial port and arduino dot matrix

#!/usr/bin/env python2.7
#MD Harrington  For  Bryan  Cairns  Void realms  re MySQL  and serial port interaction #
# Following code is  fine  with arduino dot matrix display  on its own #


import serial
import syslog
import time

#The following line is for serial over GPIO
port='/dev/ttyACM0'
baudrate=57600


ser = serial.Serial(port,baudrate,timeout=5)

with open('mytext.txt') as fp:
    lines = fp.readlines()
    for line in lines:
        m_array = line.encode('ascii')
        time.sleep(6)
        ser.write(m_array)
#Serial read section
        msg = ser.readline()
        print ("Message from arduino: ")
        print (msg)
    else:
        print "Exiting"
ser.close()
exit()