title: A simple substitution cipher in Python 2
body: <p>The code below shifts each letter of the plaintext message 2 positions in the alphabet.  The problem is this code doesn't loop back to beginning of the alphabet after the letters y and z or Y and Z. I've been trying to fix this for a bit now. What can I do to fix this?</p>
  
  <pre><code>msg = raw_input("any string goes here")
  
  cypher = ""
  
  for a in msg:
  
       cypher = cypher + chr(ord(a) + 2)
  
  print cypher 
  </code></pre>