I am running a process in a command window (Windows 7, Python 3.1) where I would like the user to abort the process by pressing the ESCape key. However, pressing the ESCape key doesn't appear to do anything :-(, the loop never breaks. I have also tried running the script from within my IDE (Wing), but again, the loop cannot be interrupted.
The following is a stripped-down version of my proof-of-concept test...
import msvcrt
import time
aborted = False
for time_remaining in range(10,0,-1):
# First of all, check if ESCape was pressed
if msvcrt.kbhit() and msvcrt.getch()==chr(27):
aborted = True
break
print(str(time_remaining)) # so I can see loop is working
time.sleep(1) # delay for 1 second
#endfor timing loop
if aborted:
print("Program was aborted")
else:
print("Program was not aborted")
time.sleep(5) # to see result in command window before it disappears!
If anyone could tell me where I might be going wrong I would be most grateful.
Python 3 strings are unicode and, therefore, must be encoded to bytes for comparison. Try this test:
if msvcrt.kbhit() and msvcrt.getch() == chr(27).encode():
aborted = True
break
Or this test:
if msvcrt.kbhit() and msvcrt.getch().decode() == chr(27):
aborted = True
break
Or this test:
if msvcrt.kbhit() and ord(msvcrt.getch()) == 27:
aborted = True
break