title: Find last index of element in list with duplicate elements python
body: <p>I have a list like this : [1,12,3,4,4,5,12,15,13,11]</p>
  
  <p>I want to find index of 12 i.e 6.
  I have tried linear approach but it is not efficient.</p>
  
  <pre><code>item = 12
  for i in range(len(mylist)):
      if mylist[i] == item:
          index = i
  return index
  </code></pre>
  
  <p>Any efficient way to get this ?</p>