title: Iterating through DataFrame row index in reverse order
body: <p>I know how to iterate through the rows of a pandas DataFrame:</p>
  
  <pre><code>for id, value in df.iterrows():
  </code></pre>
  
  <p>but now I'd like to go through the rows in reverse order (<code>id</code> is numeric, but doesn't coincide with row number). Firstly I thought of doing a sort on index <code>data.sort(ascending = False)</code> and then running the same iteration procedure, but it didn't work (it seem to still go from smaller <code>id</code> to larger).</p>
  
  <p>How can I accomplish this?</p>