title: Recompile all Python files in directory
body: <p>I have a Python directory with a number of .py files. I recently compiled them into .pyc files using <code>python -m compileall</code>. I have now changed some of the source files and would like to recompile, writing over the old .pyc files.</p>
  
  <p>Is there a quick way to do this from the command line without having to manually delete all existing .pyc files?</p>