Python is being put into an idle state by Windows and stops responding

[mikealvarrez]

Bug report

Bug description:

If I write any Python code and run it with a click, opening the Windows console, it works for the first few minutes. Five or fifteen minutes later, Windows puts my program into idle mode and it stops running.

Even if I instantiate a second thread with Flask listening for requests from a second program that is activated every five minutes by the Windows Task Scheduler.

My program simply goes into idle mode. Totally bizarre.

while True:
    print(dt.datetime.now())
    time.sleep(60)

CPython versions tested on:

3.11

Operating systems tested on:

Windows

[gvanrossum]

@mikealvarrez Version 3.11 is out of support (except for security fixes). Does this repro on later versions? Ideally on 3.14?

[benediktjohannes]

Hi! Thanks for reaching out and asking your question. I wasn’t able to reproduce the issue on my side (using the latest Python 3.15 alpha). It’s possible this was already fixed in an earlier version, or it might be related to the Windows console in your setup.

Could you please try again with the latest Python version? If the issue persists, it might be worth contacting Microsoft or checking whether a specific setting is causing it. Additionally, you could try running it in a virtual machine. Thanks in advance for any additional information!

[benediktjohannes]

And one additional question: Is this always after exactly the same amount of time (for example, always exactly 5 or 15 minutes)? Unfortunately, I wasn’t able to understand whether you meant that it appears consistently after the same time and you just don’t know whether it is 5 or 15 minutes, or whether it occurs at more random intervals.

And if it is always exactly the same time: Is this after a precise value set somewhere (like exactly 5 minutes / 300 seconds), or after a more “random” number of seconds, which could theoretically indicate some resource running out?

[tanloong]

One possibility is that the QuickEdit mode of the Windows console causes the freeze. Could you try to disable it and see if the problem persists.

See also:
https://learn.microsoft.com/en-us/answers/questions/2102924/how-to-disable-quickedit-settings-in-windows-11
https://stackoverflow.com/questions/30418886/how-and-why-does-quickedit-mode-in-command-prompt-freeze-applications

[mikealvarrez]

I discovered the source of the problem.

I think it's not exactly related to Python version XYZ, but rather to cmd.exe.

When I set bash.exe to run my script, it ran 24 hours straight.

Bizarre situation. It took me months to realize this.

[zooba]

So we can assume this is not an issue with Python? We certainly don't do anything deliberately to go into suspended mode (though if your code calls sleep you are actually requesting suspension by the OS and it may choose to do it within the constraints of its API, but that's not Python's fault), and I've got no idea what we could fix to make it stop.

[mikealvarrez]

"I've got no idea what we could fix to make it stop"