title: Convert letters to lower case
body: <p>I use the following with respect to letters from any language:</p>
  
  <pre><code>text = regex.sub("[^\p{alpha}\d]+"," ",text
  </code></pre>
  
  <p>Can I use <code>p{alpha}</code> to convert letters to their lower case equivalent if such an equivalency exists? How would this regex look?</p>