self.setDaemon(True)

def run(self):
    time.sleep(self.timeout)
os._exit(1)
alarm = Alarm(4)
alarm.start()
time.sleep(2)
del alarm
print('yup')
alarm = Alarm(4)
alarm.start()
time.sleep(8)
del alarm
print('nope')
signal.alarm replacement in Windows [Python]