How to crop a numpy 2d array to non-zero values?

Question

Let\'s say i have a 2d boolean numpy array like this:

import numpy as np
a = np.array([
    [0,0,0,0,0,0],
    [0,1,0,1,0,0],
    [0,1,1,0,0,0],
    [0,0,0,0         


        

Answer 1

a = np.transpose(a[np.sum(a,1) != 0])
a = np.transpose(a[np.sum(a,1) != 0])

It's not the quickest but it's alright.