How to draw with Python and tkinter

Let’s draw with our app… made with just Python and tkinter, all included in your Python installation.

import tkinter as tk
from PIL import ImageGrab
import os



lastx, lasty = 0, 0


def xy(event):
    """Takes the coordinates of the mouse when you click the mouse"""
    global lastx, lasty
    lastx, lasty = event.x, event.y


def addLine(event):
    """Creates a line when you drag the mouse
    from the point where you clicked the mouse to where the mouse is now"""
    global lastx, lasty
    canvas.create_line((lastx, lasty, event.x, event.y))
    # this makes the new starting point of the drawing
    lastx, lasty = event.x, event.y

def save(event, test=0):
    """ Save the image in the canvas """
    x = root.winfo_rootx()+canvas.winfo_x() # x pos of canvas
    y = root.winfo_rooty()+canvas.winfo_y() # y pos of canvas
    x1 = x + canvas.winfo_width() # width of canvas
    y1 = y + canvas.winfo_height() # height of canvas
    im = ImageGrab.grab((x, y, x1, y1))
    if test:
        print(f"{root.winfo_width()=}")
        print(f"{root.winfo_height()=}")
        print(f"{root.winfo_y()=}")
        print(f"{root.winfo_x()=}")
        print(f"{root.winfo_rooty()=}")
        print(f"{root.winfo_rootx()=}")
        print(f"{root.winfo_width()=}")
        print(x, y, x1, y1)

    if test == 0:
        im.save("captured.png")
        os.system("captured.png")

root = tk.Tk()
root.geometry("800x600")
root.columnconfigure(0, weight=1)
root.rowconfigure(0, weight=1)

canvas = tk.Canvas(root)
canvas.grid(column=0, row=0, sticky=(tk.N, tk.W, tk.E, tk.S))
canvas.bind("<Button-1>", xy)
canvas.bind("<B1-Motion>", addLine)
root.bind("<Control-s>", lambda evt: save(evt, test=0))

root.mainloop()