Help in substrings

[nilamo]

and I open it via cmd and everytime theres the eror message it just closes right away so I don't have a chance to read it

Add pause = input() to the end, so it'll stay open until you hit "enter".  That way you can see whatever error(s) there are.

Or, run it from the command line, instead of double-clicking it (which is how I'm guessing you're running it now).