#!/usr/bin/env python
# -*- coding: utf-8 -*-

import fcntl, time

myfile = open('/tmp/gigix', 'r')

try:
        fcntl.flock(myfile, fcntl.LOCK_EX|fcntl.LOCK_NB)
except IOError:
        print("Can't immediately write-lock the file, waiting...")
        fcntl.flock(myfile, fcntl.LOCK_EX)
finally:
        print('Lock acquire, sleep 30 secs...')
        time.sleep(30)
        fcntl.flock(myfile, fcntl.LOCK_UN)
        myfile.close()
        print('Bye...')