i am making a paint like app in python using tkinter and turtle. im trying to save the image drawn as a png.

short version of my program :

import tkinter as tk
from functools import partial
from turtle import TurtleScreen, RawTurtle, Shape
from PIL import Image

def draw(x, y):
    turtle.ondrag(None)
    turtle.pendown()
    turtle.goto(x, y)
    turtle.penup()
    screen.update()
    turtle.ondrag(draw)

def move(x, y):
    screen.onclick(None)
    turtle.goto(x, y)
    screen.onclick(move)
    screen.update()
    

def set_color(color):
    global pen_color
    pen_color = color
    turtle.pencolor(color)
    screen.update()
    
    # --- add widgets ---

root = tk.Tk()

canvas = tk.Canvas(root, width=500, height=500)
canvas.pack(side='right', expand=True, fill='both')

frame = tk.Frame(root)
frame.pack(side='left', fill='y')

tk.Label(frame, text='COLORS').grid(column=0, row=0)

tk.Button(frame, bg='red', width=10, command=partial(set_color, 'red')).grid(column=0, row=1)
tk.Button(frame, bg='yellow', width=10, command=partial(set_color, 'yellow')).grid(column=0, row=2)
tk.Button(frame, bg='green', width=10, command=partial(set_color, 'green')).grid(column=0, row=3)
tk.Button(frame, bg='blue', width=10, command=partial(set_color, 'blue')).grid(column=0, row=4)
tk.Button(frame, bg='black', width=10, command=partial(set_color, 'black')).grid(column=0, row=5)

def save () :
    drawing = screen.getcanvas()
    drawing.postscript(file='drawing.ps')
    img = Image.open( 'drawing.ps')
    img.save('drawing.png')
    print('...dumping gui window to png')
bsave = tk.Button(
    frame,
    text='save *',
    width=10,
    command=save
)
bsave.grid(column=0, row=6)

screen = TurtleScreen(canvas)
screen.tracer(False)

pen_color = 'black'

turtle = RawTurtle(screen)
#turtle.hideturtle()
turtle.shape("circle")
polygon = turtle.get_shapepoly()
fixed_color_turtle = Shape("compound")
fixed_color_turtle.addcomponent(polygon, "", "")
screen.register_shape('fixed', fixed_color_turtle)
turtle.shape("fixed")
turtle.penup()
turtle.pensize(5)
turtle.turtlesize(2000,2000)
turtle.ondrag(draw)
screen.onscreenclick(move)
screen.update()
screen.mainloop()

when i run this i get the error :

i would like to try something without ghostscript but most solutions ive seen involve it.

i also tried this but the x and y values returned are always wrong

def save () :
    x0 = frame.winfo_rootx()
    y0 = frame.winfo_rooty()
    x1 = x0 + frame.winfo_width()
    y1 = y0 + frame.winfo_height()
    ImageGrab.grab().crop((x0, y0, x1, y1)).save('painting.png')