Python script pausing in cmd

Question

I am running a few Python scripts at the same time. They are running in windows CMD.

I never knew that you can externally pause a Python script running in CMD.

If I hold the mouse button for a few seconds the script pauses and not just the output the execution as well.

For simplicity's sake I am showing you a very simple example:

while datetime.datetime.now().hour < 16:
    print(datetime.datetime.now())
    with open("dump.txt", "at") as f:
        f.write(f"t: {datetime.datetime.now()}\n")
    time.sleep(5)

Both the output to the file and the print to stdout stop if I squeeze the mouse button and they restart when I press enter.

I have two questions, how can I run Python that this type of stops are not possible?

The other is if there some way to detect this type of event in Python(at least the restart).

Answer 1

This happens if the "Quick Edit Mode" of the console is enabled. To temporarily disable use following code (error checks missing for brevity):

import win32console as con
import signal


# Missing constants in pywin

ENABLE_EXTENDED_FLAGS = 0x0080
ENABLE_QUICK_EDIT_MODE = 0x0040 


h = con.GetStdHandle(con.STD_INPUT_HANDLE)
oldMode = h.GetConsoleMode()

# Restore old console mode on CTRL-C 
def handler(signum, frame):
    h.SetConsoleMode(oldMode)
    exit()

signal.signal(signal.SIGINT, handler)


# Modify console mode to disable quick edit mode
h.SetConsoleMode((oldMode | ENABLE_EXTENDED_FLAGS) &
        ~ENABLE_QUICK_EDIT_MODE)


# Test
while True:
    print("a", end="")

# Final mode restore (never reached in this example)
h.SetConsoleMode(oldMode)

Based on documentation:

http://timgolden.me.uk/pywin32-docs/win32console__GetStdHandle_meth.html
http://timgolden.me.uk/pywin32-docs/PyConsoleScreenBuffer__GetConsoleMode_meth.html
http://timgolden.me.uk/pywin32-docs/PyConsoleScreenBuffer__SetConsoleMode_meth.html

https://learn.microsoft.com/en-us/windows/console/setconsolemode

http://www.gaclib.net/CodeIndexDemo/Gaclib/SourceFiles/consoleapi.h.html

Answer 2

It's actually the cmd.exe entering the so called quick edit mode to help users select the text output. here is a good explanation about that.

you can disable it for yourself via properties of cmd.exe, read here, how - (it required a restart of cmd for me).