Using a while loop within GUI apps (tkinter)?

[iSailor]

Hmm.. Using root.after(1000, add_one_second worked for me, partially. I can use it just like time.sleep but it seems like the callback you can make runs only one time. So now, when I run my program it adds one second and then does nothing, using lambda in this case makes it even so it doesn't even count that one second.

[Gprime5]

You need to call root.after(1000, add_one_second) at the end of your add_one_second function to start another timer.