import signal

def handler(sig, frame):
    print(sig)
    raise KeyboardInterrupt

signal.signal(signal.SIGINT, handler) # press Ctrl+C to trigger handler

import sys
if sys.platform == 'win32':
    print('to observe effect, run py script interactively: python -i key.py')
else:
    "threading.Event does not work on windows"
    import threading
    forever = threading.Event()
    forever.wait()