While Loop Fail - Caesar Cipher

I'm having a problem where when I ask my program to quit out it prints like I ask it to, however shows my menu of options as well continuously. So I'm getting this: >>> (

Solution 1:

x != 'q' or 'Q' is being handled as (x != 'q') or 'Q', and 'Q' is always True.

It would better be: x not in 'qQ' or x.lower() != 'q'

Solution 2:

Your problem is this line:

while x != 'q' or 'Q' :

The problem is that Q itself will always return True, so the expression will always be true. Try changing the line with:

while x != 'q' and x != 'Q' :