title: Converting raw input string to numbers (for each letter) then summing the numbers
body: <p>I want a user to enter a word e.g. <code>apple</code> and then convert each character in this string to a corresponding letter (a = 1, b = 2, c = 3 etc.)</p>
  
  <p>So far I've defined all the letters </p>
  
  <pre><code>a=1
  b=2
  c=3
  d=4 
  e=5 
  f=6 
  g=7 
  etc...
  </code></pre>
  
  <p>and have split the string to print out each letter using </p>
  
  <pre><code>word = str(raw_input("Enter a word: ").lower())
  
  for i in range (len(word)):
      print word[i]
  </code></pre>
  
  <p>this prints the characters individually, but I can't figure out how to print these as their corresponding numbers, which I could then sum together. </p>