title: How to broadcast update operation to numpy array
body: <p>Say I have an array 
  <code>A = [[0,1], [2,3]]</code>
  which is shape (2,2). 
  Then say I want to update the 0th row of A to [4,4], and the 1st row of A to [8,8], where the output is a new array of shape (2,2,2)</p>
  
  <pre><code>C = [[[4,4],[2,3]], 
        [0,1],[8,8]]] 
  </code></pre>
  
  <p>I want to do this without using a for-loop, ie, I want to do this using numpy's vectorizing features.
  Thanks</p>