The issue is your *= for x[loop5] . just do x[loop5] * 2 so it doesn't attempt to assign it to immutable x.

I tested my code on my local webpage with a number of different inputs ranging from 1 - 7 characters with and wihout alphabetic characters and all answers come up as correct and showed the results to another person and they verified it was working, so, as far as I'm concerned this is a win. My code may suck, no it really does, but it does work just won't work here. Been fun being my told doesn't work when it does.

If anyone says the problem is in your code - well tell that to the other person who saw it working.