It will help to know what terminal you're using -- classic console, Windows Terminal, ConEmu, something else?

Please try the following script to find out whether typing Ctrl-C is sending the console control event CTRL_C_EVENT (0). Typing Ctrl-Break (if available on your keyboard) should send CTRL_BREAK_EVENT (1) and exit.

import time
import ctypes

kernel32 = ctypes.WinDLL('kernel32', use_last_error=True)

CTRL_C_EVENT = 0

@ctypes.WINFUNCTYPE(ctypes.c_ulong, ctypes.c_ulong)
def handler(event):
    print('event:', event)
    if event != CTRL_C_EVENT:
        return False 
    return True

print('Type Ctrl-Break to exit.')
kernel32.SetConsoleCtrlHandler(handler, True)
while True:
    time.sleep(1)

I am using the standard windows cmd and I don't have break key on my keyboard.When runing the script it does not respond to ctrl-c.

Running the CMD shell from Explorer allocates a classic console (i.e. an instance of "conhost.exe"). It's the inherited console that matters here, not the shell.

It seems that the Ctrl-C event is disabled in the Python process. This process state is either inherited from the parent process or enabled by creating a process in a new process group (i.e. the CREATE_NEW_PROCESS_GROUP process creation flag). The CMD shell's start command creates a process in a new group when the /b option is used. This option is meant to run a background process that shouldn't be interrupted by Ctrl-C.

Here's a modified version of the above script that manually enables Ctrl-C via SetConsoleCtrlHandler(). If I'm right, this script should print "event: 0" on a new line each time that Ctrl-C is pressed.

import time
import ctypes

kernel32 = ctypes.WinDLL('kernel32', use_last_error=True)

CTRL_C_EVENT = 0

# Enable CTRL_C_EVENT for the current process.
kernel32.SetConsoleCtrlHandler(None, False)

@ctypes.WINFUNCTYPE(ctypes.c_ulong, ctypes.c_ulong)
def handler(event):
    print('event:', event)
    if event != CTRL_C_EVENT:
        return False 
    return True

kernel32.SetConsoleCtrlHandler(handler, True)

print('Type Ctrl-Break to exit.')
while True:
    time.sleep(1)

On a related note, if the Ctrl-C event is disabled, Python's console read has a bug. In this case, the canceled read gets mistakenly handled as an empty read (i.e. EOF), which is why the REPL exits. We know that typing Ctrl-C canceled the read in the console and set the last error to ERROR_OPERATION_ABORTED, so there's no reason to confuse it with EOF.

uhmm... The Problem solved itself? after restarting again it is now raising a KeyboardInterrupt, and the script above works fine

it seems that my script is disabling Ctrl-c somehow, but why would that stay even after python is reinstalled and all python processes are killed? . The Script Above does print 'event: 0', Is it suppose to exit? if so it doesn't

it seems that my script is disabling Ctrl-c somehow, but why would that stay even after python is reinstalled and all python processes are killed?

The Ctrl+C event can be disabled for a process in three ways:

• call SetConsoleCtrlHandler(NULL, TRUE)
• inherit the state from the parent process
• run as a new process group via CREATE_NEW_PROCESS_GROUP

The Script Above does print 'event: 0', Is it suppose to exit? if so it doesn't

No, it's an infinite loop. Desktop keyboards have a pause/break key, in which case Ctrl-Break sends CTRL_BREAK_EVENT (1), for which the default handler calls ExitProcess(). Most laptops have some way to type the break key, such as Fn-B, in which case use Fn-Ctrl-B or maybe just Fn-B. See keyboards without break key.