title: How to get first non-null item in list
body: <p>How would I grab the following:</p>
  
  <pre><code>l=[None, None, 'hello', 'hello']
  first(l) ==&gt; 'hello'
  
  l = [None, None, None, None]
  first(l) ==&gt; None
  </code></pre>
  
  <p>I could try doing it with a list comprehension, but that would then error if it had no items.</p>