title: Accessing elements of arrays within an array
body: <p>Example:</p>
  
  <pre><code>matrix = np.zeros((2, 2), dtype=np.ndarray)
  matrix[0, 0] = np.array([1, 2])
  matrix[0, 1] = np.array([3, 4])
  matrix[1, 0] = np.array([5, 6])
  matrix[1, 1] = np.array([7, 8])
  </code></pre>
  
  <p>I would like to create a matrix from the left entries of each array, i.e.</p>
  
  <pre><code>[[1, 3], [5, 7]]
  </code></pre>
  
  <p>Is there a shorthand way of doing this? I have tried <code>matrix[:,:][0]</code> but this doesn't yield what I want...</p>
  
  <p>Any help would be much appreciated!</p>