Find indices of elements equal to zero in a NumPy array

Question

NumPy has the efficient function/method nonzero() to identify the indices of non-zero elements in an ndarray object. What is the most efficient way to obtain th

Answer 1

There is np.argwhere,

import numpy as np
arr = np.array([[1,2,3], [0, 1, 0], [7, 0, 2]])
np.argwhere(arr == 0)

which returns all found indices as rows:

array([[1, 0],    # Indices of the first zero
       [1, 2],    # Indices of the second zero
       [2, 1]],   # Indices of the third zero
      dtype=int64)