def handle_timeout():
  ... important cleanup logic ...

signal.signal(signal.SIGALRM, handle_timeout)  # <-- why no TypeError here?
signal.alarm(MY_APPLICATION_TIME_LIMIT)

... do stuff and then if we take too long ...

# py2: TypeError: handle_timeout() takes no arguments
# py3: TypeError: handle_timeout() takes 0 positional arguments but 2 were given