title: Indexing in numpy arrays
body: <p>I am trying various ways for slicing a numpy arrray. I thought that both the print statements will yield the same output. But they are not. Can anyone explain me why?</p>
  <pre><code>import numpy as np
  two_dim_array = np.array([[1,2,3,4],[5,6,7,8],[9,10,11,12],[13,14,15,16]])
  print(two_dim_array)
  print(two_dim_array[[0,1],[2,3]]) #-----&gt; why wont this work?
  print(two_dim_array[:2,[2,3]])   #-----&gt; why would this work?
  </code></pre>