python pid file

Install lockfile:
$ pip install lockfile
Choose your path, remember is has to be writable by the user who invokes your python program. Here's an example:

	import sys
	from time import sleep
	from lockfile.pidlockfile import PIDLockFile
	if __name__ == '__main__':
	# If we can't acquire a lock in 1 second, raise an exception.
	with PIDLockFile('/home/me/script.pid', timeout=1):
	while True:
	sys.stdout.write('Check /home/me/script.pid for my process id\n')
	sleep(1)

view raw lockfile.py hosted with ❤ by GitHub

As long as the process is running there will be a file named /home/me/script.pid containing the process id; this PID file can be used as a lock file to prevent multiple processes from running at the same time, in case that wasn't already obvious :)
https://github.com/openstack/pylockfile