I scoured internet for answer to no avail. I am new to python and was toying with large calculations, 99999**999999999 for instance, and Idle started running and became completely non responsive. Ctrl-c didn't work. The menu in shell became non-responsive. I had to x-out & restart Idle. There's got to be a way to stop a process from executing in Idle. If there is not, that's ashamed. I repeated the 99999**999999999 numerous times to see if I couldn't figure it out, but couldn't. Each time the window hazed over and the run wheel thing kept spinning and couldn't be stopped. This is merely a curiosity.