Python Script not exiting with keyboard Interrupt

Question

I made a simple script to take screenshots and save it to a file every few seconds. Here is the script :

from PIL import ImageGrab as ig
import time
from datetime import datetime

try :
    while (1) :
        tm = datetime.today().strftime('%Y-%m-%d-%H:%M:%S')
        try :
            im = ig.grab()
            im.save('/home/user/tmp/' + tm + '.png')
            time.sleep(40)
        except :
            pass
except KeyboardInterrupt:
    print("Process interrupted")
    try :
        exit(0)
    except SystemExit:
        os._exit(0)
        

It works perfectly (in Ubuntu 18.04, python3), but the keyboard interrupt does not work. I followed this question and added the except KeyboardInterrupt: statement. It again takes a screenshot when I press CTRL+C. Can someone help with this?

Answer 1

You need to move your keyboard interrupt exception handling one up. The keyboard interrupt never reaches your outer try/except block.

You want to escape the while loop; exceptions inside the while block are handled here:

while True:
    tm = datetime.today().strftime('%Y-%m-%d-%H:%M:%S')
    try :
        im = ig.grab()
        im.save('/home/user/tmp/' + tm + '.png')
        time.sleep(40)
    except :   # catch keyboard interrupts and break from loop
        pass

If you break from the loop on keyboard interrupt, you leave the while loop and it won't grab again.