title: how can i sort a list of Multidimension?
body: <p>While studying sort using the key parameter (Lamda x: x), I have a question.</p>
  <p>I understand that I can use the key parameter to determine the alignment condition. just like below.</p>
  <pre><code>list1 = [1, 2, 3, 4, 5, 6, 7, 8, 9]
  
  print(sorted(list1, key=lambda x: -x))
  &gt;&gt; [9, 8, 7, 6, 5, 4, 3, 2, 1]
  </code></pre>
  <p>I also know it's possible on a Double brackets list.</p>
  <pre><code>list2 = [[1,9], [2,8], [3,7], [4,6], [5,5], [6,4]]
  
  print(sorted(list2, key=lambda x: x[1]))
  &gt;&gt; [[6, 4], [5, 5], [4, 6], [3, 7], [2, 8], [1, 9]]
  </code></pre>
  <p>What I'm curious about is, can I set the alignment condition in the Triple brackets list? <br>
  For example, how can I sort the list below in ascending order of the third element? <br></p>
  <pre><code>list3 = [[[1, 2, 3], [2, 3, 4], [3, 4, 5], [4, 5, 6]], [[5, 6, 7], [6, 7, 8], [7, 8, 9], [8, 9, 1]]]
  # possible to sort it like below? in order of third element of Triple square brackets
  &gt;&gt; [[[8, 9, 1], [1, 2, 3], [2, 3, 4], [3, 4, 5], [4, 5, 6]], [[5, 6, 7], [6, 7, 8], [7, 8, 9]]]
  </code></pre>
  <p>Also, is it possible to sort lists contain element with no brackets, double brackets, and triple brackets? <br>
  Something like</p>
  <pre><code>list4 = [ 5, 1, 3, [ [[4],[5]], [6] ], [1,2,3], [1,[2,3]]]
  &gt;&gt; [ 5, 1, 3, [1,2,3], [1,[2,3]], [ [[4],[5]], [6] ]] # The order is from the lower list.
  </code></pre>