Preventing Windows OS from sleeping while your python code runs

Do you have a python script that you want to run through to completion, but might take several hours without user interaction?

Might you run on a laptop or other Windows computer that has power management enabled, so that it might go to sleep or hibernate when not being used?

If you do nothing, windows will likely sleep or hibernate before your script can complete.

The following simple piece of code can prevent this problem. When used, it will ask windows not to sleep while the script runs. (In some cases, such as when the battery is running out, Windows will ignore your request.)

class WindowsInhibitor:

    '''Prevent OS sleep/hibernate in windows; code from:

    https://github.com/h3llrais3r/Deluge-PreventSuspendPlus/blob/master/preventsuspendplus/core.py

    API documentation:

    https://msdn.microsoft.com/en-us/library/windows/desktop/aa373208(v=vs.85).aspx'''

    ES_CONTINUOUS = 0x80000000

    ES_SYSTEM_REQUIRED = 0x00000001

    def __init__(self):

        pass

    def inhibit(self):

        import ctypes

        print("Preventing Windows from going to sleep")

        ctypes.windll.kernel32.SetThreadExecutionState(

            WindowsInhibitor.ES_CONTINUOUS | \

            WindowsInhibitor.ES_SYSTEM_REQUIRED)

    def uninhibit(self):

        import ctypes

        print("Allowing Windows to go to sleep")

        ctypes.windll.kernel32.SetThreadExecutionState(

            WindowsInhibitor.ES_CONTINUOUS)

To run it, simply:

import os

osSleep = None

# in Windows, prevent the OS from sleeping while we run

if os.name == 'nt':

    osSleep = WindowsInhibitor()

    osSleep.inhibit()

# do slow stuff

if osSleep:

    osSleep.uninhibit()

It is based on code from here, which also has code for preventing suspension on Linux under GNOME and KDE, should you need that.