title: Get intersecting rows across two 2D numpy arrays
body: <p>I want to get the intersecting (common) rows across two 2D numpy arrays. E.g., if the following arrays are passed as inputs:</p>
  
  <pre><code>array([[1, 4],
         [2, 5],
         [3, 6]])
  
  array([[1, 4],
         [3, 6],
         [7, 8]])
  </code></pre>
  
  <p>the output should be:</p>
  
  <pre><code>array([[1, 4],
         [3, 6])
  </code></pre>
  
  <p>I know how to do this with loops. I'm looking at a Pythonic/Numpy way to do this.</p>