movement in a zigzag in a 2d array

[ShakeDat53]

I need to move in a zigzag (like snakes and ladders) from the start to the end of the grid.
Here's my code so far:

import random
def cls():
    print("\n" * 100)
    # clears screen

def create_grid():
    # create a 2d array with the specified dimensions & contents called 3 times to create the 3 game tables
    grid = []
    for x in range(7):
        grid.append([])
        for y in range(7):
            grid[x].append("  ")

    for i in range(7):
        a = i + 1
        b = 14 - i
        c = 15 + i
        d = 28 - i
        e = 29 + i
        f = 42 - i
        g = 43 + i
        string1 = str(a)
        string2 = "0" + string1
        grid[6][i] = string2
        grid[5][i] = str(b)
        grid[5][6] = "08"
        grid[5][5] = "09"
        grid[4][i] = str(c)
        grid[3][i] = str(d)
        grid[2][i] = str(e)
        grid[1][i] = str(f)
        grid[0][i] = str(g)
    return grid
print(create_grid())
def roll_dice():
    roll_one = random.randint(1, 6)
    roll_two = random.randint(1, 6)
    return roll_one, roll_two

def move_counter():
    move = 0
    return move

def starter_position():
    p1_x_current = 0
    p1_y_current = 6
    p1_x_previous = 0
    p1_y_previous = 6
    p2_x_current = 0
    p2_y_current = 6
    p2_x_previous = 0
    p2_y_previous = 6
    return p1_x_current, p1_y_current, p1_x_previous, p1_y_previous, p2_x_current, p2_y_current, p2_x_previous, p2_y_previous

def movement(move, p1_x_current, p1_y_current, p1_x_previous, p1_y_previous, p2_x_current, p2_y_current, p2_x_previous, p2_y_previous):
    dice_roll = roll_dice()
    move

    position

def print_grid(grid):
    print("-" * (7 * 4))
    for y in range(0, 7):
        print("|" + "|".join(grid[y]) + "|")
        print("-" * (7 * 4))
        grid[6][0] = ' p'
print(print_grid(create_grid()))

[ichabod801]

dir = 1
for row in list_of_rows:
    for column in row[::dir]:
        ....
    dir *= -1