title: numpy random shuffle by row independently
body: <p>I have the following array:</p>
  
  <pre><code> a= array([[  1,  2, 3],
             [  1,  2, 3],
             [  1,  2, 3])
  </code></pre>
  
  <p>I understand that <code>np.random,shuffle(a.T)</code> will shuffle the array along the row, but what I need is it to shuffe each row idependently. How can this be done in numpy? Speed is critical as there will be several million rows.</p>
  
  <p>For this specific problem, each row will contain the same starting population.</p>