title: Python XML parsing with complicated structure (timestamp)
body: <p>How can I properly parse the follwoing xml codes?
  I have tried a number of other examples codes, but they seem not work in my case.
  Especially for the comma separated data structure.</p>
  
  <p>This one might be simple:</p>
  
  <pre><code>   &lt;parameter&gt;
     &lt;parameterName&gt;Device.DMversion&lt;/parameterName&gt;
     &lt;parameterValue type="xs:string"&gt;02.00&lt;/parameterValue&gt;
     &lt;/parameter&gt;
  </code></pre>
  
  <p>But this one is a little bit complicated:</p>
  
  <pre><code>&lt;parameter&gt;
  &lt;parameterName&gt;Device.LANDevice.1.WLANConfiguration.1.AssociationHistory.1.MACAddress&lt;/parameterName&gt;
  &lt;parameterValue type="xs:string"&gt;aa:bb&lt;/parameterValue&gt;
  &lt;/parameter&gt;
  &lt;parameter&gt;
  &lt;parameterName&gt;Device.LANDevice.1.WLANConfiguration.1.AssociationHistory.1.AssociationTime&lt;/parameterName&gt;
  &lt;parameterValue type="xs:dateTime"&gt;2013-05-31T07:30:39-07:00&lt;/parameterValue&gt;
  &lt;/parameter&gt;
  </code></pre>
  
  <p>A little more complicated:
  Timestamp values are changing right after "ClientStats": 4-->5-->6
  And I like to average parameterValues for all timestampes.</p>
  
  <pre><code>&lt;parameter&gt;
  &lt;parameterName&gt;Device.LANDevice.1.WLANConfiguration.1.AssociatedDevice.1.ClientStats.4.CLIENT_STATS_Index&lt;/parameterName&gt;
  &lt;parameterValue type="xs:unsignedInt"&gt;3&lt;/parameterValue&gt;
  &lt;/parameter&gt;
  &lt;parameter&gt;
  &lt;parameterName&gt;Device.LANDevice.1.WLANConfiguration.1.AssociatedDevice.1.ClientStats.5.CLIENT_STATS_Index&lt;/parameterName&gt;
  &lt;parameterValue type="xs:unsignedInt"&gt;3&lt;/parameterValue&gt;
  &lt;/parameter&gt;&lt;parameter&gt;
  &lt;parameterName&gt;Device.LANDevice.1.WLANConfiguration.1.AssociatedDevice.1.ClientStats.6.CLIENT_STATS_Index&lt;/parameterName&gt;
  &lt;parameterValue type="xs:unsignedInt"&gt;3&lt;/parameterValue&gt;
  &lt;/parameter&gt;
  </code></pre>