title: Creating rank 3 numpy arrays
body: <p>I would like to create a rank 3 array, using numpy, such that the array resembles a stack of 9x9 rank 2 arrays. Each of these arrays will be completely filled with ones, twos, threes, etc.</p>
  
  <p>So, looking at one face of the cube we see ones, at the opposite face nines. And then at the sides columns where each column contains a number between 1 and 9. </p>
  
  <p>Hopefully I've made this clear. I can do it for a rank 2 array, just not a rank 3 array. </p>