title: What does the python re.template function do?
body: <p>While using the re module in ipython I noticed an undocumented <code>template</code> function:</p>
  
  <pre><code>In [420]: re.template?
  Type:           function
  Base Class:     &lt;type 'function'&gt;
  String Form:    &lt;function template at 0xb7eb8e64&gt;
  Namespace:      Interactive
  File:           /usr/tideway/lib/python2.7/re.py
  Definition:     re.template(pattern, flags=0)
  Docstring:
      Compile a template pattern, returning a pattern object
  </code></pre>
  
  <p>there is also a flag <code>re.TEMPLATE</code> and its alias <code>re.T</code>.</p>
  
  <p>None of this is mentioned in the docs for either 2.7 or 3.2.  What do they do?  Are they obsolete hangovers from an earlier version of Python, or an experimental feature that may be officially added in the future?</p>