title: Accessing chunks at once in a numpy array
body: <p>Provided a numpy array:</p>
  
  <pre><code>arr = np.array([0,1,2,3,4,5,6,7,8,9,10,11,12])
  </code></pre>
  
  <p>I wonder how access chosen size <strong>chunks</strong> with chosen separation, both concatenated and in slices:</p>
  
  <p>E.g.: obtain chunks of size 3 separated by two values:</p>
  
  <pre><code>arr_chunk_3_sep_2 = np.array([0,1,2,5,6,7,10,11,12])
  arr_chunk_3_sep_2_in_slices = np.array([[0,1,2],[5,6,7],[10,11,12])
  </code></pre>
  
  <p>Wha is the most efficient way to do it? If possible, I would like to avoid copying or creating new objects as much as possible. Maybe <strong>Memoryviews</strong> could be of help here?</p>