title: Python: Make last item of array become the first
body: <p>This is a very simple question, but I haven't seem to be able to find a satisfactory answer for it.</p>
  
  <p>What is the best way, in Python, make the last item of a list become the first one "pushing" the rest of the list.</p>
  
  <p>Something that does:</p>
  
  <pre><code>&gt;&gt;&gt; a=[1,2,3,4]
  &gt;&gt;&gt; a[?????]
  [4, 1, 2, 3]
  </code></pre>
  
  <p>I know I can always play with <code>len</code>, list concatenation...</p>
  
  <pre><code>&gt;&gt;&gt; a=[1,2,3,4]
  &gt;&gt;&gt; [a[len(a)-1]] + a[0:len(a)-1]
  [4, 1, 2, 3]
  </code></pre>
  
  <p>But that doesn't look right... "<em>Pythonic</em>", if you may</p>
  
  <p>Thank you in advance.</p>