Python 如何通过 KeyboardInterrupt 退出无限 while 循环

Question

我的while循环在按下Ctrl+C时没有退出。它似乎忽略了我的KeyboardInterrupt异常。循环的部分看起来是这样的：

while True:
  try:
    if subprocess_cnt <= max_subprocess:
      try:
        notifier.process_events()
        if notifier.check_events():
          notifier.read_events()
      except KeyboardInterrupt:
        notifier.stop()
        break
    else:
      pass
  except (KeyboardInterrupt, SystemExit):
    print '\nkeyboardinterrupt found!'
    print '\n...Program Stopped Manually!'
    raise

我还是不太确定问题出在哪里，但我的终端甚至没有打印出我在异常处理里放的两个打印提示。有人能帮我找出这个问题吗？

Answer 1

把你的 break 语句换成 raise 语句，像下面这样：

while True:
  try:
    if subprocess_cnt <= max_subprocess:
      try:
        notifier.process_events()
        if notifier.check_events():
          notifier.read_events()
      except KeyboardInterrupt:
        notifier.stop()
        print 'KeyboardInterrupt caught'
        raise  # the exception is re-raised to be caught by the outer try block
    else:
      pass
  except (KeyboardInterrupt, SystemExit):
    print '\nkeyboardinterrupt caught (again)'
    print '\n...Program Stopped Manually!'
    raise

在 except 块里的两个打印语句应该会执行，并且 '(again)' 会在第二个打印出来。