title: python list append versus extend for dictionaries
body: <p>I have some confusion regarding python's <code>append</code> vs. <code>extend</code> on a list which is supposed to contain dictionaries:</p>
  
  <pre><code>holder = []
  
  element = {}
  
  element["id"] = 1
  element["value"] = 2
  
  holder.append(element)
  
  print(holder)
  </code></pre>
  
  <p>prints as expected <code>[{'id': 1, 'value': 2}]</code></p>
  
  <p>however if I use: <code>holder.extend(element)</code> instead of <code>holder.append(element)</code> the output will be: <code>['id', 'value']</code></p>
  
  <p>Can someone explain me why? (<a href="https://stackoverflow.com/questions/252703/python-append-vs-extend">append vs. extend</a> does not apply for this)</p>