How to access the adjacent cells of each elements of matrix in python?

Question

Here two cells are considered adjacent if they share a boundary. For example :

A = 5 6 4
    2 1 3
    7 9 8

Here adjacent elements to index 0,0 is at index [0,1] and [1,0] and for index 1,1 the adjacent elements are at index [0,1],[1,0],[2,1] and [1,2].

Answer 1

Supposed you have mxn matrix, and you want to find the adjacent indices of the cell (i, j):

def get_adjacent_indices(i, j, m, n):
   adjacent_indices = []
    if i > 0:
        adjacent_indices.append((i-1,j))
    if i+1 < m:
        adjacent_indices.append((i+1,j))
    if j > 0:
        adjacent_indices.append((i,j-1))
    if j+1 < n:
        adjacent_indices.append((i,j+1))
    return adjacent_indices