Swap zeros in numpy matrix

Question

I have a numpy matrix like so:

array([[2,  1, 23, 32],
       [34, 3, 3, 0],
       [3, 33, 0, 0],
       [32, 0, 0, 0]], dtype=int32)

Now

Answer 1

You can also use numpy.argsort with advanced indexing:

arr[np.arange(arr.shape[0])[:, None], (arr != 0).argsort(1, kind="mergesort")]

#array([[ 2,  1, 23, 32],
#       [ 0, 34,  3,  3],
#       [ 0,  0,  3, 33],
#       [ 0,  0,  0, 32]], dtype=int32)