Python in a Nutshell

Termination Functions

The atexit module lets you register termination functions (i.e., functions to be called at program termination, last in, first out). Termination functions are similar to clean-up handlers established by try/finally. However, termination functions are globally registered and called at the end of the whole program, while clean-up handlers are established lexically and called at the end of a specific try clause. Both termination functions and clean-up handlers are called whether the program terminates normally or abnormally, but not when the termination is caused by calling os._exit. Module atexit supplies a single function called register.