How can i get the number coordinate column last digit of the double digits in line with the single digits

Question

there's a grid in a seperate text file and the function reads this file and returns an object consisting of the grid where the text file is read line by line

my issue is that in my numerical coordinates the single digit doesn't align with the last digit of the double digit numbers

def load_board(filename):
    result = "  "
    with open(filename) as f:
        print(f)
        for index, line in enumerate(f):
            if index == 0:
                result += ' '+' '.join([chr(alphabets + 65) for alphabets in range(len(line) - 1)]) + '\n' #the alphabetical column heading

            result += f"{-(index + 1)+(20)}"
            if (len(result))<2:
                 result+=' '.join(result)
       
            for characters in line:
                result += " " + (characters)
        return result

def save_board(filename, board):
    with open(filename, "wt") as f:
        f.write(board)

b = load_board("l19.txt")
print(b)
save_board("l19b.txt", b)

this gives me an output of

   A B C D E F G H I J K L M N O P Q R S
19 . . . . @ @ @ . O O . . @ . O O O . O 
18 @ O O @ O @ . . @ O @ O . . . @ @ . @ 
17 @ O . . @ O . O O O O O . O O O O O @ 
16 . . @ @ . O O . @ . . O @ O . @ . O . 
15 O . @ . @ . O @ . O O @ @ O . . O @ O 
14 O . . . O O O @ . @ @ . . . @ . O @ @ 
13 . . @ O @ . . @ . . O O O . @ . @ . . 
12 . . @ @ . @ @ @ . . . @ O . O . . . @ 
11 @ O . . @ . @ @ @ @ O . . @ O O O @ O 
10 @ . . O . @ @ O @ O O @ @ . @ . O @ . 
9 @ O O O . . @ O . . @ @ O @ @ @ . O O 
8 @ @ O @ . O O O . @ . O @ . @ @ @ . @ 
7 @ . O . O @ O O . O O . @ O @ . . @ O 
6 @ . . . O @ @ O O @ . @ @ . . O . O . 
5 O O @ @ . . O @ @ . @ . @ . O @ @ O . 
4 @ . O . . O O . @ O @ O @ O O . @ @ . 
3 @ @ O O @ . O . @ . O @ . @ O @ O . . 
2 . . . O O @ @ O . @ O . O . @ O O @ . 
1 @ @ . @ O . @ @ . . @ O O O O O @ @ @

i tried to get it aligned by adding a conditional statement stating that if the length of the number is less than 2 to add a space however it didn't work

Answer 1

Use the options of f-string to format as a 2 length value, so you can remove the useless if (len(result))<2: block

You can also simplify using string.ascii_uppercase

from string import ascii_uppercase

def load_board(filename):
    result = "  "
    with open(filename) as f:
        for index, line in enumerate(f):
            # the alphabetical column heading
            if index == 0:
                result += ' ' + ' '.join(ascii_uppercase[:len(line) - 1]) + '\n'
            # the number prefix
            result += f"{19 - index:2d}"
            # the chars
            result += ' ' + ' '.join(line.strip()) + '\n'
    return result