Rearrange columns of numpy 2D array

Question

Is there a way to change the order of the columns in a numpy 2D array to a new and arbitrary order? For example, I have an array

array([[10, 20, 30, 40, 50],         


        

Answer 1

I have a matrix based solution for this, by post-multiplying a permutation matrix to the original one. This changes the position of the elements in original matrix

import numpy as np

a = np.array([[10, 20, 30, 40, 50],
       [ 6,  7,  8,  9, 10]])

# Create the permutation matrix by placing 1 at each row with the column to replace with
your_permutation = [0,4,1,3,2]

perm_mat = np.zeros((len(your_permutation), len(your_permutation)))

for idx, i in enumerate(your_permutation):
    perm_mat[idx, i] = 1

print np.dot(a, perm_mat)