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 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.

Ans:

#First I copied the grid as the author instructs

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

['.','0','0','.','.','.'],

['0','0','0','0','.','.'],

['0','0','0','0','0','.'],

['.','0','0','0','0','0'],

['0','0','0','0','0','.'],

['0','0','0','0','.','.'],

['.','0','0','.','.','.'],

['.','.','.','.','.','.']]

# I set two global variables x and y. I will use x to iterate through

# the while loop and y to increment the index in the inner list

x = 0

y = 0

# set the condition for the while loop to limit it to the length of the list

# and also to limit it to the length of the inner list which doesn't exceed index 5

while x < len(grid) and y <= 5:

for item in range(len(grid)):

print(grid[item][y], end='')

y += 1 # increment y after iteration of a for loop

print('') # print blank line

x += 1 # increment x after iteration of for loop go through for loop again

Aleternate so;ution using zip(*grid)

print('\n'.join(map(''.join, zip(*grid))))