title: Progress indicator during pandas operations
body: <p>I regularly perform pandas operations on data frames in excess of 15 million or so rows and I'd love to have access to a progress indicator for particular operations.</p>
  
  <p>Does a text based progress indicator for pandas split-apply-combine operations exist?</p>
  
  <p>For example, in something like:</p>
  
  <pre><code>df_users.groupby(['userID', 'requestDate']).apply(feature_rollup)
  </code></pre>
  
  <p>where <code>feature_rollup</code> is a somewhat involved function that take many DF columns and creates new user columns through various methods.  These operations can take a while for large data frames so I'd like to know if it is possible to have text based output in an iPython notebook that updates me on the progress.</p>
  
  <p>So far, I've tried canonical loop progress indicators for Python but they don't interact with pandas in any meaningful way.</p>
  
  <p>I'm hoping there's something I've overlooked in the pandas library/documentation that allows one to know the progress of a split-apply-combine.  A simple implementation would maybe look at the total number of data frame subsets upon which the <code>apply</code> function is working and report progress as the completed fraction of those subsets.</p>
  
  <p>Is this perhaps something that needs to be added to the library?</p>