title: Python check list is correclty ordered when same element values order is not guaranteed
body: <p>So I have two list with ids and scores</p>
  <pre><code>ids = [1,2,3,5,6,7]
  scores = [5., 5. , 4., 3., 2., 1.]
  </code></pre>
  <p>When I do an argsort of scores to later index ids the order is not guaranteed when two elements have similar value.</p>
  <p>So the argsort for scores can either be:
  <code>[5, 4, 3, 2, 1, 0]</code> or <code>[5, 4, 3, 2, 0, 1]</code></p>
  <p>When i use those index to slide ids then sorted_ids could be</p>
  <pre><code>sorted_ids = [7,6,5,3,2,1]
  or
  sorted_ids = [7,6,5,3,1,2]
  </code></pre>
  <p>I would like a method that given the scores they were sorted on will say both <code>sorted_ids</code> are &quot;equal&quot;.</p>