Numpy reshape/restack?

Question

Say I have a 2 x 8 x 3 array, like so:

array([[[ 0,  1,  2],
    [ 1,  2,  3],
    [ 2,  3,  4],
    [ 3,  4,  5],
    [ 4,  5,  6],
    [ 5,  6,  7],
    [ 6,  7,  8],
    [ 7,  8,  9]],

   [[10, 11, 12],
    [11, 12, 13],
    [12, 13, 14],
    [13, 14, 15],
    [14, 15, 16],
    [15, 16, 17],
    [16, 17, 18],
    [17, 18, 19]]])

How do I reshape it so that it becomes an 8 x 2 x 3 array with elements like

[[[ 0,  1,  2],
  [10, 11, 12]],
 [[ 1,  2,  3],
  [11, 12, 13]],
...

reshape(8, 2, 3) gives the following result, which is not what I want:

array([[[ 0,  1,  2],
    [ 1,  2,  3]],

   [[ 2,  3,  4],
    [ 3,  4,  5]],

   [[ 4,  5,  6],
    [ 5,  6,  7]],

   [[ 6,  7,  8],
    [ 7,  8,  9]],

   [[10, 11, 12],
    [11, 12, 13]],

   [[12, 13, 14],
    [13, 14, 15]],

   [[14, 15, 16],
    [15, 16, 17]],

   [[16, 17, 18],
    [17, 18, 19]]])

If it works for a general second dimension (not just m=2), even better. Thank you!

Answer 1

Swap the first two axes.

np.swapaxes(a,0,1)