title: Store indexes of each element of list in Python
body: <p>I am trying to store indexes of each element of array which have repeated number in python using dictionary.</p>
  <pre><code>arr=[1,1,3,2,2]
  </code></pre>
  <p>desired output should be <code>{1:0,1:1,3:2,2:3,2:4}</code>
  instead of that index of previous element overwriten by new elemnt index giving <code>{1:1,3:2,2:4}</code></p>