title: importer which imports .py files only
body: <p>I need a Python <a href="http://legacy.python.org/dev/peps/pep-0302/" rel="nofollow">http://legacy.python.org/dev/peps/pep-0302/</a> finder and importer class which works on a specific directory, but it can load only <code>.py</code> files (i.e. no <code>.so</code>, no <code>.dll</code>, no <code>.pyc</code>).</p>
  
  <p>The specified directory contains several packages (with <code>__path__</code> specified and overridden from the default <code>__path__</code> added for <code>__init__.py</code>).</p>
  
  <p>Also I need a loader which doesn't create <code>.pyc</code> files, and doesn't use any of the Python 2.6-specific solutions (e.g. <code>sys.dont_write_bytecode = True</code>, <code>python -B</code> or <code>PYTHONDONTWRITEBYTECODE</code>).</p>