Python 2.7 - How to check if SHIFT-Key or CTRL+Key is pressed?

Question

I wrote a small routine in python 2.7, which waits for some time (say, 10 minutes) but immediately exits if a key is pressed by the the user.

I'm on Windows (7, 64-bit), so I tried using the msvcrt library:

import sys
import msvcrt
from time import sleep

   def sleep_sec(secstosleep, allowskip = True):
       waitinterval_ms = 0.050
       nwaits = int(secstosleep * 1000 / waitinterval)

       sys.stdout.write("\n    Sleeping for %s seconds. You can press CTRL-F12 to skip.\n\n" % secstosleep)
       for sl in range(0, nwaits + 1):
           sleep(waitinterval_ms)
           if allowskip:
               # Check if User has pressed CTRL-F12 to stop waiting
               if = msvcrt.kbhit():
                   kp = msvcrt.getch()
                   if kp == '\xe0':
                        print "\a"  # Beep once
                        sys.stdout.write("\nSleep interrupted by User\n")
                        break

In effect it works quite well, except for the fact that it will break if the user hits either F12, F11 or Cursor Up key: I found out that if I press F12, getch() will return the '\xe0', but it seems the same code is also returned by the other mentioned keys; no way to trap CTRL, SHIFT, ALT, etc.

I would like to force the user pressing CTRL-F12, instead, to avoid quitting the wait by inadvertently hitting one of those keys.

Am I doing something wrong? Is there a way to intercept CTRL, ALT or SHIFT being pressed along with another key?

Thanks in advance, Max - Italy

Answer 1

From the msvcrt manual for msvcrt.getch():

[..] If the pressed key was a special function key, this will return '\000' or '\xe0'; the next call will return the keycode.

Just call getch() again to get the actual keycode