The atexit module defines a single function to register
cleanup functions. Functions thus registered are automatically
executed upon normal interpreter termination.
Note: the functions registered via this module are not called when the program is killed by a
signal, when a Python fatal internal error is detected, or when
os._exit() is called.
This is an alternate interface to the functionality provided by the
sys.exitfunc variable.
Note: This module is unlikely to work correctly when used with other code
that sets sys.exitfunc. In particular, other core Python modules are
free to use atexit without the programmer's knowledge. Authors who
use sys.exitfunc should convert their code to use
atexit instead. The simplest way to convert code that sets
sys.exitfunc is to import atexit and register the function
that had been bound to sys.exitfunc.
Register func as a function to be executed at termination. Any
optional arguments that are to be passed to func must be passed
as arguments to register().
At normal program termination (for instance, if
sys.exit() is called or the main module's execution
completes), all functions registered are called in last in, first out
order. The assumption is that lower level modules will normally be
imported before higher level modules and thus must be cleaned up
later.