title: How to extend an existing key in a dict?
body: <p>I want to extend an existing key in a dict with an information.
  The key <code>'abc'</code> should then be completed with a <code>'d'</code> so that the result is <code>'abcd'</code>.
  Something like this:</p>
  <pre><code>info1='abc'
  info2='d'
  DataDict[info1 '%i' %info2] = DataDict.pop(info1)
  </code></pre>
  <p>but it does not work...</p>