How to run one last function before getting killed in Python?

Question

Is there any way to run one last command before a running Python script is stopped by being killed by some other script, keyboard interrupt etc.

Answer 1

You could use the atexit module. With it, you can register a function which will be called at program termination. An example from here: http://docs.python.org/library/atexit.html

try:
    _count = int(open("/tmp/counter").read())
except IOError:
    _count = 0

def incrcounter(n):
    global _count
    _count = _count + n

def savecounter():
    open("/tmp/counter", "w").write("%d" % _count)

import atexit
atexit.register(savecounter)

You can also pass positional and keyword parameters to the function you want to call at program termination.

Note that there are a few circumstances listed in the docs in which your handler won't be called:

Note: The functions registered via this module are not called when the program is killed by a signal not handled by Python, when a Python fatal internal error is detected, or when os._exit() is called.

As such, you may want to also register a signal handler.