title: Sort multilayer dictionary by sorting second layer dictionary
body: <p>How can I sort a multilayer  dictionary by rearrange the second layer dictionary's keys? I think an example would be a better way to present it.    </p>
  
  <p>The original multilayer dictionary:<br>
  <code>{'John': {'Low &gt;3 days': 3,'Low &gt;1 day': 2,'High &lt;1 day': 2,'High &gt;3 days': 3,'Low &lt;1 day': 1,'High &gt;1 day': 1},'Mary': {'High &gt;1 day': 5,'High &gt;3 days': 1,'Low &lt;1 day': 0, 'Low &gt;1 day': 2, 'Low &gt;3 days': 9, 'High &lt;1 day': 5}}</code></p>
  
  <p>I am trying to arrange the second layer dictionary with change the first layer dictionary and move the second layer key-value pair together at the same time. The order of the second layer dictionary key is <code>High &lt;1 day, Low &lt;1 day, High &gt;1 day, Low &gt;1 day, High &gt;3 days, Low &gt;3 days.</code> The expected output would be as follow:<br>
  <code>{'John': {'High &lt;1 day': 2,'Low &lt;1 day': 1,'High &gt;1 day': 1,'Low &gt;1 day': 2,'High &gt;3 days': 3,'Low &gt;3 days': 3},'Mary': {'High &lt;1 day': 5,'Low &lt;1 day': 0,'High &gt;1 day': 5,'Low &gt;1 day': 2,'High &gt;3 days': 1,'Low &gt;3 days': 9}}</code></p>