title: List slicing with negative step size
body: <p>Why does the below code returns an empty list when it should return <code>[4,  3,  2]</code> (because of the negative step size):</p>
  
  <pre><code>i = [  0,  1,  2,  3,  4,  5,  6,  7,  8,  9]
     #[  0,  1,  2,  3,  4,  5,  6,  7,  8,  9]
     #[-10, -9, -8, -7, -6, -5, -4, -3, -2, -1]
  s = i[2:-5:-1]
  print(s)
  </code></pre>