title: Apply function to each element of a list
body: <p>Suppose I have a list like:</p>
  <pre><code>mylis = ['this is test', 'another test']
  </code></pre>
  <p>How do I apply a function to each element in the list? For example, I want to be able to apply <code>str.upper</code> to get</p>
  <pre><code>['THIS IS TEST', 'ANOTHER TEST']
  </code></pre>