title: Incremental code coverage for Python unit tests?
body: <p>How can I get an <strong>incremental</strong> report on code coverage in Python? </p>
  
  <p>By "incremental", I mean what has been the change in the covered lines since some "last" report, or from a particular Git commit.</p>
  
  <p>I'm using <code>unittest</code> and <code>coverage</code> (and coveralls.io) to get the code coverage statistics, which work great. But I'm involved only with a part of the project, and at first I'm concerned with what <strong>my last commit</strong> has changed. I expected <code>coverage</code> to be able to show the difference between two reports, but so far have not found anything short of running textual diff on HTML output.</p>