title: Get average value from list of dictionary
body: <p>I have lists of dictionary. Let's say it</p>
  
  <pre><code>total = [{"date": "2014-03-01", "value": 200}, {"date": "2014-03-02", "value": 100}{"date": "2014-03-03", "value": 400}]
  </code></pre>
  
  <p>I need get maximum, minimum, average value from it. I can get max and min values with below code:</p>
  
  <pre><code>print min(d['value'] for d in total)
  print max(d['value'] for d in total)
  </code></pre>
  
  <p>But now I need get average value from it. How to do it?</p>