Finding an algorithm to split text evenly inside an image with Pillow/Python

Question

I'm trying to convert text into an image with pillow and python, with the help of this answer + I added some lines to make the text split into columns in order to make a square image because the code of the answer shows the text in just one tall column. here's an example output of a large text file(it's just a thumbnail because the original image is large):

you can see in the bottom right that there's empty space, that happens because the text lines are not split evenly, I tried everything, I hope someone can help me fix it.

here's how I want it to look: (without the empty space in the bottom right) to do this, the script must split the lines evenly between the columns.

THANK YOU

here's the code

import PIL, math, os
import PIL.Image
import PIL.ImageFont
import PIL.ImageOps
import PIL.ImageDraw

def text_image(text_path, font_path=None):
    with open(text_path) as text_file:
        lines = tuple(l.rstrip() for l in text_file.readlines())

    large_font = 15
    font_path = font_path or 'font.ttf'
    try:
        font = PIL.ImageFont.truetype(font_path, size=large_font)
    except IOError:
        font = PIL.ImageFont.load_default()
        print('Could not use chosen font. Using default.')

    pt2px = lambda pt: int(round(pt * 96.0 / 72))
    max_width_line = max(lines, key=lambda s: font.getsize(s)[0])

    test_string = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
    max_height = pt2px(font.getsize(test_string)[1])
    max_width = pt2px(font.getsize(max_width_line)[0])
    mw = font.getsize(max_width_line)[0]
    mh = font.getsize(max_width_line)[1]
    height = max_height * len(lines)
    width = int(round(max_width + 40))
    
    block = int(mw/mh)
    squareBlock = int(math.sqrt(len(lines)/(mw/mh))) + 1
    
    squareImageSize = block * squareBlock * block
    
    image = PIL.Image.new('L', (squareImageSize, squareImageSize), color=PIXEL_OFF)
    draw = PIL.ImageDraw.Draw(image)
    
    vertical_position = 20
    horizontal_position = 20
    line_spacing = int(round(max_height * 0.8))
    i = 0
    for e, line in enumerate(lines):
        draw.text((horizontal_position, vertical_position),
                  line, fill=PIXEL_ON, font=font)
        vertical_position += line_spacing
        
        if e % block == 0 and not e==0:
            i+=1
        if i == squareBlock:
            i = 0
            horizontal_position += mw - 20
            vertical_position = 20

    a, b, c, d = PIL.ImageOps.invert(image).getbbox()
    image = image.crop((0,0,c+20,d+20))
    
    return image