Python: how to print out a 2d list that is formatted into a grid?

Question

Currently, I have made this code

def grid_maker(h,w):
    grid = [[[\"-\"] for i in range(w)] for i in range(h)]
    grid[0][0] = [\"o\"]
    print grid

>         


        

Answer 1

If you want to "pretty" print your grid with each sublist on its own line, you can use pprint:

>>> grid=[[['o'], ['-'], ['-'], ['-'], ['-']], [['-'], ['-'], ['-'], ['-'], ['-']], [['-'], ['-'], ['-'], ['-'], ['-']]]

>>> from pprint import pprint
>>> pprint(grid)

[[['o'], ['-'], ['-'], ['-'], ['-']],
 [['-'], ['-'], ['-'], ['-'], ['-']],
 [['-'], ['-'], ['-'], ['-'], ['-']]]

It will still show each element as a list, as you defined it, if you want to show them as strings you'll have to use joins like m.wasowski suggests.

Answer 2

Use string join()

for row in grid:
    print ''.join(*zip(*row))

or as one-liner:

print '\n'.join(''.join(*zip(*row)) for row in grid)

but if would rather recommend you to change everything into:

def grid_maker(h,w):
    grid = [["-" for _ in range(w)] for _ in range(h)]
    grid[0][0] = "o"
    return grid

print '\n'.join(''.join(row) for row in grid_maker(5,5))

Answer 3

If you want to use the result of grid_maker(), you have to return its result, using return:

def grid_maker(h, w):
    grid = [["-" for i in range(w)] for i in range(h)]
    grid[0][0] = "o"
    return grid

I modified it, because I don't think that each element must be inside another list.

To print the "grid", you could iterate through each row and then iterate through each element:

def print_grid(grid):
    for row in grid:
        for e in row:
            print e,
        print

Output:

print_grid(grid_maker(3, 5))

o - - - -
- - - - -
- - - - -