title: Can't understand the output of this python code (loop on a list)
body: <p>can someone explains how this code works step by step?</p>
  <pre><code>a = [0, 1, 2, 3]
  for a[-1] in a:
    print(a[-1])
  </code></pre>
  <p>Output:
  0
  1
  2
  2</p>