Set up a python script to be called on startup of the machine, the script can be started and stopped using sudo testservice start | stop. Script should be copied to /etc/init.d and made executable.

gistfile1.txt

#!/bin/bash
# /etc/init.d/testservice

# Provides:          testservice
# Required-Start:    $remote_fs $syslog
# Required-Stop:     $remote_fs $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Example initscript
# Description:       This service is used to start a python script
### END INIT INFO


case "$1" in 
    start)
        echo "Starting testservice"
        /home/pi/python/service.py &
        ;;
    stop)
        echo "Stopping testservice"
        pid=`ps -ef | grep '[p]ython /home/pi/python/service.py' | awk '{ print $2 }'`
    echo $pid
    kill $pid
    sleep 2
    echo "Service killed."
    ;;
    *)
        echo "Usage: /etc/init.d/testservice start|stop"
        exit 1
        ;;
esac

exit 0

service.py

#!/usr/bin/python
import logging
import time
logging.basicConfig(filename='service.log',level=logging.INFO, format='%(asctime)s %(message)s')
var = 1
while var==1:
   logging.info("log message")  
   time.sleep(15)