How to create a 2D tile-map in python ASCII style

Question

Still learning about python programming and I wanted to create a little map like below but the thing is I know a for loop will draw down not draw across. However, I want to change the size of the area and add new tiles later on. I understand that this might be a really bad question but I cannot wrap my head around this.

posX = 0
posY = 0

tile1 = 'X'
tile2 = 'O'

width = int(12)
height = int(9)

'''

<--- 12 --->
XXXXXXXXXXXX ^
XOOOOOOOOOOX |
XOOOOOOOOOOX |
XOOOOOOOOOOX 
XOOOOOOOOOOX 9
XOOOOOOOOOOX 
XOOOOOOOOOOX |
XOOOOOOOOOOX |
XXXXXXXXXXXX v

'''


#Draws down and across
for i in range(width):
    print(tile1 * width)

Answer 1

You can split it on three elements and only one need for-loop

1. Top line XXXXXXXXXXXX

   print(tile1 * width)
   

2. Middle lines XOOOOOOOOOOX

   There will be height-2 lines and they will have "X", next "O" * (width-2), next "X"

   for i in range(height-2):
       print(tile1 + (tile2 * (width-2)) + tile1)
   

3. Bottom line XXXXXXXXXXXX

   print(tile1 * width)
   

Code:

posX = 0
posY = 0

tile1 = 'X'
tile2 = 'O'

width = 12   # no need `int()`
height = 9   # no need `int()`

# top line

print(tile1 * width)

# middle lines

for i in range(height-2):
    print(tile1 + (tile2 * (width-2)) + tile1)

# bottom line

print(tile1 * width)

---

EDIT:

To make it useful put all lines on list - i.e all_lines - using append() instead of print(). But keep every line as list of chars instead of string with all chars (I will use [ ] in code to do it).

It means

['X', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'X']

instead of

XOOOOOOOOOOX

And then you can easily replace elements

all_lines[1][1] = '@'

where you have positions [Y][X] not [X][Y] - all_lines[Y][X] or in other words all_lines[row][col]

posX = 0
posY = 0

tile1 = 'X'
tile2 = 'O'

width = 12   # no need `int()`
height = 9   # no need `int()`

all_lines = []

# top line

all_lines.append([tile1] * width)

# middle lines
for i in range(height-2):
    all_lines.append([tile1] + ([tile2] * (width-2)) + [tile1])

# bottom line

all_lines.append([tile1] * width)

print(all_lines)

and this gives 2D list

[
  ['X', 'X', 'X', 'X', 'X', 'X', 'X', 'X', 'X', 'X', 'X', 'X'], 
  ['X', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'X'], 
  ['X', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'X'], 
  ['X', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'X'], 
  ['X', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'X'], 
  ['X', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'X'], 
  ['X', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'X'], 
  ['X', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'O', 'X'], 
  ['X', 'X', 'X', 'X', 'X', 'X', 'X', 'X', 'X', 'X', 'X', 'X']
]

and you can display it using for-loop and "".join()

for line in all_lines:
    print("".join(line))  # <-- join list of chars to one string and display it

Result with @

XXXXXXXXXXXX
X@OOOOOOOOOX
XOOOOOOOOOOX
XOOOOOOOOOOX
XOOOOOOOOOOX
XOOOOOOOOOOX
XOOOOOOOOOOX
XOOOOOOOOOOX
XXXXXXXXXXXX

---

EDIT:

To work with map you can also use other for-loop

for y in range(height):
    for x in range(width):
        print(all_lines[y][x], end='')  # draw without going to new line
    print()  # go to new line

and then you can use it with extra if/else to test or change elements

for y in range(height):
    for x in range(width):
        if all_lines[y][x] == '@':
           all_lines[y][x] = '%'
        #print(all_lines[y][x], end='')
    #print()

You can also use more Pythonic method with enumerate

for y, line in enumerate(all_lines):
    for x, item in enumerate(line):
        if item == '@':
           all_lines[y][x] = '%'  # it has to replace in original `all_lines`
        #print(item, end='')
    #print()