Скачать или смотреть How to Properly Restart a Python Script and Exit Gracefully

A guide on effectively restarting a Python script and ensuring it can exit properly when required. Learn to overcome limitations with `sys.exit()` and `os.system()`.
---
This video is based on the question https://stackoverflow.com/q/66778922/ asked by the user 'JueK3y' ( https://stackoverflow.com/u/14883370/ ) and on the answer https://stackoverflow.com/a/66781413/ provided by the user 'JueK3y' ( https://stackoverflow.com/u/14883370/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Python: Restart script and exit it after function does not work

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
How to Properly Restart a Python Script and Exit Gracefully

In Python programming, managing the flow of execution is crucial, especially in user-interactive applications. Many developers encounter a common issue: they need the ability to restart their script based on user input and exit gracefully when needed. Here, we’ll explore a well-structured solution to this problem, ensuring that users can restart the program or exit it without any complications.

The Problem

When developing a Python script, you might want to give users the option to play again or to exit the program after completing certain actions. However, issues can arise, such as:

The program restarts even when the user chooses to exit.

Standard exit commands like sys.exit() or quit() don't function as expected after a restart.

Here’s an illustrative snippet of the original method used by some developers:

[[See Video to Reveal this Text or Code Snippet]]

What Went Wrong?

Using os.system('main.py') restarts the game, but doesn't terminate the previous execution, leading to issues with leftover variables and program states.

Traditional exit commands such as quit() and exit() do not seem to function in the expected manner when the program needs to restart.

The Solution

The good news is that this issue can be resolved. Here's a step-by-step breakdown of the correct approach you can take to ensure a clean restart and proper termination of the script:

Create a Main Driver File

You'll use another file, let's call it main.py, to encapsulate the game logic.

[[See Video to Reveal this Text or Code Snippet]]

Modify Game Logic

In your game_logic function, you will implement proper exit and restart logic. Here's how you can effectively allow users to restart or exit:

[[See Video to Reveal this Text or Code Snippet]]

How This Works

Input Handling: The loop captures user input and validates it until the user provides either '1' (to restart) or '2' (to exit).

Restarting with os.system(): When the user opts to restart, os.system('main.py') invokes a new instance of the main file, effectively starting the game anew.

Exiting the Current Instance: The use of exit() immediately after restarting the program ensures that the current script instance terminates effectively, avoiding lingering variable states from the previous run.

Conclusion

By following these structured steps, you can implement a robust system within your Python application to restart scripts when necessary and exit gracefully as required. This not only enhances user experience but also improves the overall performance and reliability of your application.

Implement this method in your projects and encounter ease in managing script flow and user interaction as you develop interactive Python applications. Happy coding!