# [Tutor] Making Doubly Linked List with Less Lines of Code.

WolfRage wolfrage8765 at gmail.com
Fri Jan 2 05:48:18 CET 2015

```Final Code Using 2d List instead of Doubly Linked List.

class GameTile():

def __init__(self, id, **kwargs):

# id is (X,Y)

self.id = id

class GameGrid():

def __init__(self, **kwargs):

self.cols = 7

self.rows = 8

# grid is 2d array as y, x ie [y][x].

self.grid = [[None] * self.rows for i in range(self.cols)]

def make_grid(self):

for row in range(0, self.rows):

for col in range(0, self.cols):

self.grid[col][row] = GameTile(id=str(row) + ',' + str(col))

def print_by_row(self):

for col in range(0, self.cols):

for row in range(0, self.rows):

print(self.grid[col][row].id)

def print_by_col(self):

for row in range(0, self.rows):

for col in range(0, self.cols):

print(self.grid[col][row].id)

def check_bounds(self, x, y):

if (0 <= x < self.rows) and (0 <= y < self.cols):

return True

return False

def lookup_node(self, x, y):

if not self.check_bounds(x, y):

return False

return self.grid[y][x]

def draw_grid(self):

for col in range(0, self.cols):

print(end='| ')

for row in range(0, self.rows):

print(self.grid[col][row].id, end=' | ')

print()

temp = GameGrid()

temp.make_grid()

temp.draw_grid()

Any feedback for my code is appreciated. Thank you.

On 12/31/2014 06:57 PM, Steven D'Aprano wrote:
> Trust me on this, there is no linked list code you can write in Python
> that will be faster than using a list of lists. Even in C, traversing
> a linked list is slower than array access, and Python is not C.
OK. I do trust you.
> Bounds checking is easy: cell [i, j] is in bounds if this is true:
>
>      (0 <= i < NUM_ROWS) and (0 <= j < NUM_COLS)
>