> import numpy as np
> a = np.arange(8).reshape(4, -1)
> print(a)
[[0 1]
 [2 3]
 [4 5]
 [6 7]]
> b = np.arange(8, 16).reshape(4, -1)
> print(b)
[[ 8 9]
 [10 11]
 [12 13]
 [14 15]]
> c = np.column_stack((a, b))
> print(c)
[[ 0 1 8 9]
 [ 2 3 10 11]
 [ 4 5 12 13]
 [ 6 7 14 15]]
> d = np.row_stack((a, b))
> print(d)
[[ 0 1]
 [ 2 3]
 [ 4 5]
 [ 6 7]
 [ 8 9]
 [10 11]
 [12 13]
 [14 15]]