title: Change permissions for folder, all subfolders, and all files
body: <p>I am trying to call <code>shutil.rmtree(some_folder)</code>, but it is causing an error that another process is using some file in the subtree.  This is not the case, so I'm assuming permissions are not set correctly.  </p>
  
  <p>How can I change the permissions of all subfolders and files under some root to writeable, so I can call shutil.rmtree and get rid of them?</p>
  
  <p>Thanks</p>