title: Remove duplicates from a python list so that the last instance remains
body: <p>Let's say I have the following list:</p>
  <pre><code>start = [1, 2, 3, 1, 3, 4, 5, 3, 2]
  </code></pre>
  <p>I want to remove the duplicates so that the <strong>last</strong> instance remains. So the result would be:</p>
  <pre><code>result = [1, 4, 5, 3, 2]
  </code></pre>
  <p>I've written the following function:</p>
  <pre><code>def keep_last_instances(start):
      result = []
      
      total_counts = Counter(start)
      current_counts = {}
      for x in start:
          total_count = total_counts[x]
          current_count = current_counts.get(x, 0) + 1
  
          if current_count == total_count:
              result.append(x)
          else:
              current_counts[x] = current_count
      
      return result
  </code></pre>
  <p>Is there a faster/cleaner way?</p>