Time-Limited Input? [duplicate]

Question

What I would like to be able to do is ask a user a question using input. For example:

print('some scenario') prompt = input("You have 10 seconds to choose the correct answer...\n") 

and then if the time elapses print something like

print('Sorry, times up.') 

Any help pointing me in the right direction would be greatly appreciated.

Answer 1

If it is acceptable to block the main thread when user haven't provided an answer:

from threading import Timer  timeout = 10 t = Timer(timeout, print, ['Sorry, times up']) t.start() prompt = "You have %d seconds to choose the correct answer...\n" % timeout answer = input(prompt) t.cancel() 

Otherwise, you could use @Alex Martelli's answer (modified for Python 3) on Windows (not tested):

import msvcrt import time  class TimeoutExpired(Exception):     pass  def input_with_timeout(prompt, timeout, timer=time.monotonic):     sys.stdout.write(prompt)     sys.stdout.flush()     endtime = timer() + timeout     result = []     while timer() < endtime:         if msvcrt.kbhit():             result.append(msvcrt.getwche()) #XXX can it block on multibyte characters?             if result[-1] == '\r':                 return ''.join(result[:-1])         time.sleep(0.04) # just to yield to other processes/threads     raise TimeoutExpired 

Usage:

try:     answer = input_with_timeout(prompt, 10) except TimeoutExpired:     print('Sorry, times up') else:     print('Got %r' % answer) 

On Unix you could try:

import select import sys  def input_with_timeout(prompt, timeout):     sys.stdout.write(prompt)     sys.stdout.flush()     ready, _, _ = select.select([sys.stdin], [],[], timeout)     if ready:         return sys.stdin.readline().rstrip('\n') # expect stdin to be line-buffered     raise TimeoutExpired 

Or:

import signal  def alarm_handler(signum, frame):     raise TimeoutExpired  def input_with_timeout(prompt, timeout):     # set signal handler     signal.signal(signal.SIGALRM, alarm_handler)     signal.alarm(timeout) # produce SIGALRM in `timeout` seconds      try:         return input(prompt)     finally:         signal.alarm(0) # cancel alarm