title: How to get Number of files touched, Number of lines added, Number of lines removed from for commit in repo.iter_commits(branch) using python git?
body: <p>I would like to store the following info per commit like so,</p>
  <pre><code>for commit in repo.iter_commits(branch):
      author_name=commit.author.name
      commit_id=commit
      commit_authored_date=datetime.datetime.fromtimestamp(commit.authored_date)
      commit_committed_date=datetime.datetime.fromtimestamp(commit.committed_date)
      num_files_touched=?
      num_lines_added=?
      num_lines_removed=?
  </code></pre>
  <p>how can I do this?</p>