count-neighbours.py

def count_neighbours(grid, row, col):
    begR = max(row - 1, 0)
    begC = max(col - 1, 0)
    endR = min(row + 2, len(grid))
    endC = min(col + 2, len(grid[0]))

    sum = 0
    for r in range(begR, endR):
        for c in range(begC, endC):
            sum += grid[r][c]

    return sum - grid[row][col]


if __name__ == '__main__':
    #These "asserts" using only for self-checking and not necessary for auto-testing
    assert count_neighbours(((1, 0, 0, 1, 0),
                             (0, 1, 0, 0, 0),
                             (0, 0, 1, 0, 1),
                             (1, 0, 0, 0, 0),
                             (0, 0, 1, 0, 0),), 1, 2) == 3, "1st example"
    assert count_neighbours(((1, 0, 0, 1, 0),
                             (0, 1, 0, 0, 0),
                             (0, 0, 1, 0, 1),
                             (1, 0, 0, 0, 0),
                             (0, 0, 1, 0, 0),), 0, 0) == 1, "2nd example"
    assert count_neighbours(((1, 1, 1),
                             (1, 1, 1),
                             (1, 1, 1),), 0, 2) == 3, "Dense corner"
    assert count_neighbours(((0, 0, 0),
                             (0, 1, 0),
                             (0, 0, 0),), 1, 1) == 0, "Single"