Fill a matrix from a matrix of indices

Question

I want to fill a matrix from an array of indices :

import numpy as np

indx = [[0,1,2],[1,2,4],[0,1,3],[2,3,4],[0,3,4]]
x = np.zeros((5,5))
for i in range(5)         


        

Answer 1

Use advanced-indexing after intialization -

x[np.arange(len(indx))[:,None], indx] = 1