title: Case insensitive 'in'
body: <p>I love using the expression</p>
  
  <pre><code>if 'MICHAEL89' in USERNAMES:
      ...
  </code></pre>
  
  <p>where <code>USERNAMES</code> is a list.</p>
  
  <hr>
  
  <p>Is there any way to match items with case insensitivity or do I need to use a custom method? Just wondering if there is a need to write extra code for this.</p>