# numpy.nonzero () in Python

It returns a tuple of arrays, one for each dimension arr, containing the indices of the nonzero elements in that dimension.
The corresponding nonzero values ​​in the array can be obtained using ` arr [nonzero (arr)] `. To group indices by element rather than size, we can use ` transpose (nonzero (arr)) `.

Syntax: numpy. nonzero (arr)

Parameters:
arr: [array_like] Input array.

Return : [tuple_of_arrays] Indices of elements that are non-zero.

Code # 1: Work

 ` # Python program explaining ` ` # non-null () function ` ` `  ` import ` ` numpy as geek ` ` arr ` ` = ` ` geek.array ([[` ` 0 ` `, ` ` 8 ` `, 0 ], [ 7 , 0 , 0 ], [ - 5 , 0 , 1 ]]) ````   print ( "Input array:" , arr)    out_tpl = geek .nonzero (arr) print ( "Indices of non zero elements:" , out_tpl)  ```

Output:

Input array:
[[0 8 0]
[7 0 0]
[-5 0 1]]
Indices of non zero elements: (array ([0, 1, 2, 2], dtype = int64), array ([1, 0, 0 , 2], dtype = int64))

Code # 2:

 ` # Python getter ` ` # Corresponding nonzero values: ` ` out_arr ` ` = ` ` arr [geek.nonzero (arr)] `   ` print ` ` (` ` "Output array of non- zero number: "` `, out_arr) `

Output:

` Output array of non-zero number: [8 7 -5 1] `

Code # 3:

 ` # Python program for grouping indexes ` ` # by element, not by size `   ` out_ind ` ` = ` ` geek.transpose (geek.nonzero (arr)) ` ` `  ` print ` ` (` `" indices of non-zero number: "` `, out_ind) `

Output:

` indices of non-zero number: [[0 1] [1 0] [2 0] [2 2 ]] `