title: Iterating through list of list in Python
body: <p>I want to iterate through list of list.<br>
  I want to iterate through irregularly nested lists inside list also.<br>
  Can anyone let me know how can I do that?</p>
  
  <pre><code>x = [u'sam', [['Test', [['one', [], []]], [(u'file.txt', ['id', 1, 0])]], ['Test2', [], [(u'file2.txt', ['id', 1, 2])]]], []]
  </code></pre>