Python convex hull

import copy from tkinter import Button from tkinter import Canvas from tkinter import NORMAL from tkinter import PhotoImage from tkinter import Tk from convex_hull import compute_hull def draw_point(canvas, x, y): return canvas.create_image((x, y), image=ram, state=NORMAL) def add_point(event): draw_point(w, event.x, event.y) points.append((event.x, event.y)) return def draw_hull(): hull = copy.copy(compute_hull(points)) hull.append(hull[0]) for i in range(0, len(hull) - 1): x1 = hull[i][0] y1 = hull[i][1] x2 = hull[i + 1][0] y2 = hull[i + 1][1] w.create_line(x1, y1, x2, y2, width=3) return if __name__ == '__main__': master, points = Tk(), list() submit_button = Button(master, text="Draw Hull", command=draw_hull) submit_button.pack() quit_button = Button(master, text="Quit", command=master.quit) quit_button.pack() canvas_width = 1000 canvas_height = 800 w = Canvas(master, width=canvas_width, height=canvas_height) ram = PhotoImage(file="ram-sm.gif") w.pack() w.bind('<Button-1>', add_point) w.mainloop()