How to Exit a Python script?
Exiting a Python script refers to the process of termination of an active python process. In this article, we will take a look at exiting a python program, performing a task before exiting the program, and exiting the program while displaying a custom (error) message.
Exiting a Python application
There exist several ways of exiting a python application. The following article has explained some of them in great detail.
Example: Exit Using Python exit() Method
Python3
this is the first statement
Detecting Script exit
Sometimes it is required to perform certain tasks before the python script is terminated. For that, it is required to detect when the script is about to exit. atexit is a module that is used for performing this very task. The module is used for defining functions to register and unregister cleanup functions. Cleanup functions are called after the code has been executed. The default cleanup functions are used for cleaning residue created by the code execution, but we would be using it to execute our custom code.
In the following code, we would be defining (and registering) a function that would be called upon the termination of the program. First, the atexit module is imported. Then exit_handler() function is defined. This function contains a print statement. Later, this function is registered by passing the function object to the atexit.register() function. In the end, there is a call to print function for displaying GFG! in the output. In the output, the first line is the output of the last print statement in the code. The second line contains the output of exit_handler function that is called upon the code execution (as a cleanup function).
Not all kinds of exits are handled by the atexit module.