title: Same variable name for different values in nested loops.
body: <p>This code is perfectly valid Python</p>
  
  <pre><code>x=[[1,2,3,4], [11,22,33,44]]
  for e in x:
      for e in e:
          print e
  </code></pre>
  
  <p>Can someone please tell me why, and how this works?</p>
  
  <p>I understand that both the <code>e</code>'s are in different scopes, but how come using them together like this isn't causing an error?</p>