title: Merge two numpy arrays into a list of lists of tuples
body: <p>I haven't been able to figure this out. Thanks for any help:</p>
  
  <p>Have:</p>
  
  <pre><code>&gt;&gt;&gt; x = np.array([[1,2],[5,6]])
  &gt;&gt;&gt; x
  array([[1, 2],
         [5, 6]])
  &gt;&gt;&gt; y = np.array([[3,4],[7,8]])
  &gt;&gt;&gt; y
  array([[3, 4],
         [7, 8]])
  </code></pre>
  
  <p>Want:</p>
  
  <pre><code>&gt;&gt;&gt; z = [[(1,2),(3,4)],[(5,6),(7,8)]]
  &gt;&gt;&gt; z
  [[(1, 2), (3, 4)], [(5, 6), (7, 8)]]
  </code></pre>