title: Merging Numpy Arrays into 2D array
body: <p>I have 2 numpy arrays like this:</p>
  <pre class="lang-py prettyprint-override"><code>    a = [[a,b,c],
           [d,e,f]]
      b = [[g,h,i],
          [k,l,m]]
  </code></pre>
  <p>I want to merge them into another numpy array, something like following:</p>
  <pre class="lang-py prettyprint-override"><code>c = [[[a,g],[b,h],[c,i]],
      [[d,k],[e,l],[f,m]]]
  </code></pre>
  <p>How can I do it?</p>