title: Remove sublist from DEEP nestedlist
body: <p>I'm struggling with some NESTED LISTS.
  Briefly, inside the list of lists I have some lists containing several value</p>
  
  <pre><code>biglist = [[['strings', '632'], ['otherstrings', 'hey']],[['blabla', '924'], ['histring', 'hello']]]
  </code></pre>
  
  <p>from this nested list, I'd like to remove the sublist in which <code>'hello'</code> string appears.
  I tried this:</p>
  
  <pre><code>for sub_line in big_list:
      if 'hello' in sub_line:
          big_list.remove(sub_line)
  </code></pre>
  
  <p>Now, if I print the new <code>big_list</code> outside the loop, I get the old list since I didn't assign the updated list to a new list. But if I assign to a new list like:</p>
  
  <pre><code>for sub_line in big_list:
      if 'hello' in sub_line:
          updated_list = big_list.remove(sub_line)
  print(updated_list)
  </code></pre>
  
  <p>I get an <code>AttributeError: 'NoneType' object has no attribute 'remove'</code>.</p>
  
  <p>So what's the problem with this?
  I CANNOT use list indexing because my real list is huge and the target value is not always in the same place. 
  I've already check other questions but nothing is working.
  Thank you all!</p>