Why does the calculated width and height in pixel of a string in Tkinter differ between platforms?

Question

I have a Python script which needs to calculate the exact size of arbitrary strings displayed in arbitrary fonts in order to generate simple diagrams. I can easily do it wit

Answer 1

After searching for ages I finally found out a way to get the width of some text in any font and size!

from tkinter import *

Window = Tk()
Window.geometry("500x500+80+80")

frame = Frame(Window) # this will hold the label
frame.pack(side = "top")

# CALCULATE:
measure = Label(frame, font = ("Purisa", 10), text = "The width of this in pixels is.....", bg = "yellow")
measure.grid(row = 0, column = 0) # put the label in
measure.update_idletasks() # this is VERY important, it makes python calculate the width
width = measure.winfo_width() # get the width

# PROOF IT WORKS:
canvas = Canvas(frame, width = 400, height = 200, bg = "light green")
canvas.grid(row = 1, column = 0, columnspan = 100) # collumnspan is 100 so that the line lines up with the text
line = canvas.create_line(0, 10, width, 10, width = 4) # make a line the same length as the text
canvas.create_text(10, 20, font = ("Purisa", 10), text = "... "+str(width)+" Pixels", anchor = "nw")

The line I make is proof that this works for any font.

I have tested this for different fonts and sizes, as far as I know it works.

This is a picture of the output: