title: Pandas insert or update?
body: <p>If I'm doing df.update() on a frame for which the key doesn't exist, what's the cleanest way I can add it?</p>
  
  <p>Something like:</p>
  
  <pre><code>try:
    df.update(new_data)
  except:
    df.insert(new_data)
  </code></pre>