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Automate the Boring Stuff with Python -- Chapter 04 -- Character Picture Grid

Character Picture Grid Problem

Say you have a list of lists where each value in the inner lists is a one-character string, like this:

grid = [['.', '.', '.', '.', '.', '.'],
        ['.', 'O', 'O', '.', '.', '.'],
        ['O', 'O', 'O', 'O', '.', '.'],
        ['O', 'O', 'O', 'O', 'O', '.'],
        ['.', 'O', 'O', 'O', 'O', 'O'],
        ['O', 'O', 'O', 'O', 'O', '.'],
        ['O', 'O', 'O', 'O', '.', '.'],
        ['.', 'O', 'O', '.', '.', '.'],
        ['.', '.', '.', '.', '.', '.']]

You can think of grid[x][y] as being the character at the x- and y-coordinates of a “picture” drawn with text characters. The (0, 0) origin will be in the upper-left corner, the x-coordinates increase going right, and w the y-coordinates increase going down. Copy the previous grid value, and write code that uses it to print the image.

..OO.OO..
.OOOOOOO.
.OOOOOOO.
..OOOOO..
...OOO...
....O....

Hint: You will need to use a loop in a loop in order to print grid[0][0], then grid[1][0], then grid[2][0], and so on, up to grid[8][0]. This will finish the first row, so then print a newline. Then your program should print grid[0][1], then grid[1][1], then grid[2][1], and so on. The last thing your program will print is grid[8][5].

Also, remember to pass the end keyword argument to print() if you don’t want a newline printed automatically after each print() call.

grid = [['.', '.', '.', '.', '.', '.'],
['.', 'O', 'O', '.', '.', '.'],
['O', 'O', 'O', 'O', '.', '.'],
['O', 'O', 'O', 'O', 'O', '.'],
['.', 'O', 'O', 'O', 'O', 'O'],
['O', 'O', 'O', 'O', 'O', '.'],
['O', 'O', 'O', 'O', '.', '.'],
['.', 'O', 'O', '.', '.', '.'],
['.', '.', '.', '.', '.', '.']]
def dot_matrix(grid):
print('\n'.join(map(''.join, zip(*grid))))
def dot_matrix_alt(grid):
for i in zip(*grid):
print(''.join(i))
dot_matrix(grid)
dot_matrix_alt(grid)
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