title: Dictionary to a nested list, or an ordered list to a nested list
body: <p>I have a list of ints that I am trying to turn into a nested list, either using comprehensions or a for loop. I have tried a few methods and done plenty of research but I can't seem to figure it out.</p>
  <pre><code>original = [1, 6, 3, 9, 4, 5, 2, 6, 6, 7, 8, 9, 3]
  </code></pre>
  <p>From the original list I managed to create the following nested list and dictionary,</p>
  <pre><code>first_try = [[1], [2], [3], [3], [4], [5], [6], [6], [6], [7], [8], [9], [9]]
  
  d = {1: 1, 2: 1, 3: 2, 4: 1, 5: 1, 6: 3, 7: 1, 8: 1, 9: 2}
  </code></pre>
  <p>Desired output is:</p>
  <pre><code>final = [[1], [2], [3,3], [4], [5], [6,6,6], [7], [8], [9,9]]
  </code></pre>
  <p>Any tips or advice?</p>