title: Pandas Match list of URLs to check dependency
body: <p>From a list of URLs, I want to check for each value in complete_path if it is a subfolder of another row.</p>
  <p>The criteria for subfolder is:</p>
  <ul>
  <li>A subfolder starts with and fully contains the URL of a parent row URL</li>
  <li>A subfolder has more count of the backslash \ than the parent.</li>
  </ul>
  <p>Here's my pandas dataframe sample.</p>
  <pre><code>ID      complete_path
  1       Ajax
  2       Ajax\991\1
  3       Ajax\991
  4       BVB
  5       BVB\Christy
  6       BVB_Christy
  </code></pre>
  <p>Here's my output sample</p>
  <pre><code>ID      complete_path  dependency
  1       Ajax           None
  2       Ajax\991\1     1,3
  3       Ajax\991       1
  4       BVB            None
  5       BVB\Christy    4
  6       BVB_Christy    None
  </code></pre>