title: How to find all the indexes of a recurring item in a list?
body: <p>How can I find all the indexes of a recurring item? For Example:</p>
  <pre><code>list = ['A', 'A', 'B', 'A', 'B', 'B', 'A']
  </code></pre>
  <p>I want to return all occurrences of 'B', so it'd return:</p>
  <pre><code>indexes = [2, 4, 5]
  </code></pre>