title: Convert letters to numbers
body: <p>I have a bunch of letters, and cannot for the life of me figure out how to convert them to their number equivalent.</p>
  
  <pre><code>letters[1:4]
  </code></pre>
  
  <p>Is there a function</p>
  
  <pre><code>numbers['e']
  </code></pre>
  
  <p>which returns</p>
  
  <pre><code>5
  </code></pre>
  
  <p>or something user defined (ie 1994)? </p>
  
  <p>I want to convert all 26 letters to a specific value.</p>