[FIXED] How to sort numpy array column-wise consequetly?

Issue

I want to sort 2d array column-wise consequently, so if the values in one column are equal then sorting is performed by next column. For example array

[[1, 0, 4, 2, 3]
 [0, 1, 5, 7, 4]
 [0, 0, 6, 1, 0]]

must be sorted as

[[0, 0, 6, 1, 0]
 [0, 1, 5, 7, 4]
 [1, 0, 4, 2, 3]]

So rows must not be changed, only their order. How can I do that?

Solution

This should work

import numpy as np

a = np.array([[1, 0, 4, 2, 3],[0, 1, 5, 7, 4],[0, 0, 6, 1, 0]])

np.sort(a.view('i8,i8,i8,i8,i8'), order=['f0'], axis=0).view(np.int)

I get

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

f0 is the column which you want to sort by.

Answered By - anarchy