snake_squre.py

def snake(n):
    arr = [[0 for _ in range(n)] for _ in range(n)]

    value = 1
    border = 0

    while value <= n*n:
        x, y = border, border

        for y in range(border, n-border):
            arr[x][y] = value
            value += 1
            print '(%d,%d) = %2d' % (x, y, arr[x][y])

        for x in range(border+1, n-border):
            arr[x][y] = value
            value += 1
            print '(%d,%d) = %2d' % (x, y, arr[x][y])

        for y in range(n-border-2, border-1, -1):
            arr[x][y] = value
            value += 1
            print '(%d,%d) = %2d' % (x, y, arr[x][y])

        for x in range(n-border-2, border, -1):
            arr[x][y] = value
            value += 1
            print '(%d,%d) = %2d' % (x, y, arr[x][y])

        border += 1
        print '------------'

    return arr


if __name__ == '__main__':
    arr = snake(5)
    for idx_x, row in enumerate(arr):
        for idx_y, col in enumerate(row):
            print '(%d,%d) = %2d\t' % (idx_x, idx_y, col),
        print