Hi guys, new to the forums, osx and programming, having just started at university and have run into some trouble. I'm creating a program in python that basically simulates a bank teller, moderates the length of the que etc. Upon running for longer than a few virtual days it crashes leaving an error message. ill paste what i have and the error message below. bear in mind the code is not complete, but should be able to run none the less. (ignore the end graph) http://pastebin.com/fjLuj8qJ < code http://pastebin.com/E4XzzV7k < error it can be re produced on any computer by running the code and entering more than 5 or 6 days to run. does anyone have any idea how i could fix this?? many thanks.