creating a spiral array in python?

Question

Me and my mate were trying to create a fun game in python where the elements entered in the array are accessed in a spiral manner. I have tried few methods like one given be

Answer 1

Below is python3 code which transforms:

    [[0, 1, 2, 3, 4], 
    [5, 6, 7, 8, 9], 
    [10, 11, 12, 13, 14], 
    [15, 16, 17, 18, 19], 
    [20, 21, 22, 23, 24]]

to

    [[20, 19, 18, 17, 16], 
    [21, 6, 5, 4, 15], 
    [22, 7, 0, 3, 14], 
    [23, 8, 1, 2, 13], 
    [24, 9, 10, 11, 12]]

You can easily change implementation in such way how do you want...

    def spiral(X, Y):
        x = y = 0
        dx = 0
        dy = -1
        for i in range(max(X, Y) ** 2):
            if (-X / 2 < x <= X / 2) and (-Y / 2 < y <= Y / 2):
                yield x, y
                # print(x, y)
                # DO STUFF...
            if x == y or (x < 0 and x == -y) or (x > 0 and x == 1 - y):
                dx, dy = -dy, dx
            x, y = x + dx, y + dy

    spiral_matrix_size = 5
    my_list = list(range(spiral_matrix_size**2))
    my_list = [my_list[x:x + spiral_matrix_size] for x in range(0, len(my_list), spiral_matrix_size)]

    print(my_list)

    for i, (x, y) in enumerate(spiral(spiral_matrix_size, spiral_matrix_size)):
        diff = int(spiral_matrix_size / 2)
        my_list[x + diff][y + diff] = i

    print(my_list)