Найти индексы элементов во всех «восьми направлениях» 2D-массива/матрицы Python

Вы можете создать функцию, которая «стреляет» во всех направлениях от нужной точки до тех пор, пока не будет достигнут конец сетки. Возврат всех найденных точек:

def direction_points(g_len_x, g_len_y, point_x, point_y):

    result = []

    directions = [
        [0, -1],    # up
        [1, -1],    # up right
        [1, 0],     # right
        [1, 1],     # down right
        [0, 1],     # down
        [-1, 1],    # down left
        [-1, 0],    # left
        [-1, -1],   # left up
        ]

    for direction in directions:

        x = point_x
        y = point_y
        end_reached = False
        while not end_reached:

            x = x + direction[0]
            y = y + direction[1]
            if (0 <= x < g_len_x) and not end_reached:
                if (0 <= y < g_len_y) and not end_reached:
                    result.append([x, y])
                else:
                    end_reached = True
            else:
                end_reached = True

    return result

При этом вы можете создать линии или сетку:

grid_len_x = 10
grid_len_y = 12
mid_point_x = 4
mid_point_y = 6

points = direction_points(grid_len_x, grid_len_y, mid_point_x, mid_point_y)

lines = []
for y in range(grid_len_y):
    line = ''
    for x in range(grid_len_x):

        if [x, y] in points:
            line += 'X'
        else:
            if x == mid_point_x and y == mid_point_y:
                line += '0'
            else:
                line += '*'
    lines.append(line)

for line in lines:
    print(line)

Результат

****X*****
****X****X
X***X***X*
*X**X**X**
**X*X*X***
***XXX****
XXXX0XXXXX
***XXX****
**X*X*X***
*X**X**X**
X***X***X*
****X****X

Следующее предоставит индексы во всех восьми направлениях:

from itertools import product

def valid_indexes(lst, row, col):
    return row in range(len(lst)) and col in range(len(lst[0]))

# Queen's view since it's the same as what a queen in chess can 'view'
def queens_view(lst, row, col, dr=0, dc=0):
    if dr or dc:
        yield (row, col)
        if valid_indexes(lst, row+dr, col+dc):
            yield from queens_view(lst, row+dr, col+dc, dr, dc)
    else:
        for dr, dc in product([-1, 0, 1], [-1, 0, 1]):
            if dr or dc and valid_indexes(lst, row+dr, col+dc):
                yield from queens_view(lst, row+dr, col+dc, dr, dc)

start_row, start_col = 3, 4 # Index of the '0' in your list
for row, col in queens_view(lst, start_row, start_col):
    print(row, col)
    # Do what you like with the index