python - Perfect font size to fit in specific width and height -

what wanted function given image width , height , text fit text image perfect font size. achieved trial-error method. here's code:

# -*- coding: utf-8 -*-  pil import imagefont  def get_total_area(width, height):     return width * height def get_font(name, size):     return imagefont.truetype(font, size)  def fit(width, height, font, size, text):     font = get_font(font, size)     text_w, text_h = font.getsize(text)     text_area = get_total_area(text_w, text_h)     total_area = get_total_area(width, height)     if total_area>text_area:         action(size)         return true     else:         return size def action(size):     print("succes!") counter = 0 text = """one way of doing pass text default font size of, 20, imagettfbbox , retrieve width it. can calculate how smaller or bigger text should fit size want calculating scale factor:""" size = 60 font = 'my-font.ttf' while true:     counter += 1     ans = fit(500, 500, font, size, text)     if ans == true:          break     else:         size = ans         size -=1 print("font_size: {}".format(size)) print("repetitions: {} ".format(counter)) 

in specific example (from code above) takes 16 repetitions , perfect font size 45. now, investigating little in stackoverflow found questions regarding same problem , 1 solutions called attention: https://stackoverflow.com/a/10689312/5106998

so modified code follows:

# -*- coding: utf-8 -*-  pil import imagefont  def get_total_area(width, height):     return width * height def get_font(name, size):     return imagefont.truetype(font, size)  def fit(width, height, font, size, text):     font = get_font(font, size)     text_w, text_h = font.getsize(text)     text_area = get_total_area(text_w, text_h)     total_area = get_total_area(width, height)     if total_area>text_area:         action(size)         return true     else:         scale = total_area/text_area         size = int(round(size*scale))         return size def action(size):     print("succes!") counter = 0 text = """one way of doing pass text default font size of, 20, imagettfbbox , retrieve width it. can calculate how smaller or bigger text should fit size want calculating scale factor:""" size = 60 font = 'my-font.ttf' while true:     counter += 1     ans = fit(500, 500, font, size, text)     if ans == true:          break     else:         size = ans         size -=1 print("font_size: {}".format(size)) print("repetitions: {} ".format(counter)) 

the second code works not expected: takes 2 repetitions conclude perfect font size 34 (we know 45). second code, taking consideration scale factor runs lot faster.

my question is: mistake? or best approximation can using method? have other ideas tackle down problem?

i don't want perfect font size @ once, want reduce repetitions.