I'm sorry I've forgotten to add one important thing to the script - the
t.setDaemon(True) call, as without it the main thread will wait for the
user thread to stop explicitly. So the correct script is:

    some_time = 6000000 # seconds

    class MyThread(Thread):
        def run(self):
            while (True):
                time.sleep(some_time)

    t = MyThread()
    t.setDaemon(True)
    t.start()
    while(True):
        select.select(None, None, None, some_time)