Fastest way to convert a list of indices to 2D numpy array of ones

Question

I have a list of indices

a = [
  [1,2,4],
  [0,2,3],
  [1,3,4],
  [0,2]]

What\'s the fastest way to convert this to a numpy array of ones,

Answer 1

May not be the best way but the only way I can think of:

output = np.zeros((4,5))
for i, (x, y) in enumerate(zip(a, output)):
    y[x] = 1
    output[i] = y
print(output)

Which outputs:

[[ 0.  1.  1.  0.  1.]
 [ 1.  0.  1.  1.  0.]
 [ 0.  1.  0.  1.  1.]
 [ 1.  0.  1.  0.  0.]]