title: How does it work List index L[L[index]]
body: <p>Hi all I recently stepped over a indexing of a list i had never seen and do not understand. <code>List[List[index]]</code></p>
  
  <p>example</p>
  
  <pre><code>L = [1,2,3,4,5]
  
  in: L[0]
  
  out: 1
  
  in: L[L[0]]
  
  out: 2
  </code></pre>
  
  <p>Why is that? Why using L removes the first element?</p>
  
  <p>I understand if L would have list as elements but in this case?</p>
  
  <p>Thank you all for the support given to a rookie :)</p>