How to setup clean up functions

cleanup_example.py

import atexit
import signal
import time


def only_once(f):
    global called  # python 2
    called = False

    def wrapped(*args, **kwargs):
        global called  # python 2
        # nonlocal called  # python 3
        if not called:
            called = True
            f(*args, **kwargs)

    return wrapped


@only_once
def Cleanup(*args):  # *args to match signal handler function signature
    print "all cleaned up!"


# normal
atexit.register(Cleanup)

# kill <pid>
signal.signal(signal.SIGTERM, Cleanup)

# Ctrl + c
signal.signal(signal.SIGINT, Cleanup)

time.sleep(5)