title: Python list slice syntax used for no obvious reason
body: <p>I occasionally see the list slice syntax used in Python code like this:</p>
  
  <pre><code>newList = oldList[:]
  </code></pre>
  
  <p>Surely this is just the same as:</p>
  
  <pre><code>newList = oldList
  </code></pre>
  
  <p>Or am I missing something?</p>