title: Caesar cypher in Python
body: <p>I am new to python and I want to write a program that asks for a  line of input (each number will be separated by a single space.) It would use a simple letter-number substitution cipher. Each letter will be appointed a number. So 1 = a, 2 = b and 3 = c until it reaches 26 = z. From there, however, the cipher would continue on so; 27 = a, 28 = b etc. 0's will be a space. The program will only use 0's and positive numbers. It would also print out the decryption of the message. For example:</p>
  
  <p><strong>Please type a code:</strong> 8 5 12 12 15</p>
  
  <p>hello</p>
  
  <p>and another example:</p>
  
  <p><strong>Please type a code:</strong> 16 25 20 8 14 0 9 19 0 3 15 15 12</p>
  
  <p>python is cool</p>
  
  <p>At the moment i have tried turning the alphabet into a list like this;</p>
  
  <pre><code>    n = int(input("Please type a code: ")
      x =['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z']
  </code></pre>
  
  <p>...and then referring back to it later. However, im not exactly sure how this would work. I've also tried using the .replace() function. Like this:</p>
  
  <pre><code>    n = int(input("Please type a code: ")
      n = n.replace('1','a') #all the way until z and then loop it.
      print(n)
  </code></pre>
  
  <p>and so and and so on. But again, i have no idea how to do this properly.
  Any help would be greatly appreciated. Thanks.</p>