Sort Algorithm Visualization: How to pull values to animate the canvas, from inside a tight loop

Question

I am working on a visualization of different sorting algorithms using the height of different bars with tkinter. I have been able to shuffle the bars and also sort them afte

Answer 1

the time consuming function is "swap_two_pos()" which is catastrophic and you run it every loop, what you should do is finishing your sorting then redraw the bars again, below is your code modified working without GUI freeze, added a function and removed "swap_two_pos()" func.

import tkinter as tk
import random


def insertion_sort():
    global barList
    global lengthList

    for i in range(len(lengthList)):
        cursor = lengthList[i]
        cursorBar = barList[i]
        pos = i

        while pos > 0 and lengthList[pos - 1] > cursor:
            lengthList[pos] = lengthList[pos - 1]
            barList[pos], barList[pos - 1] = barList[pos - 1], barList[pos]
            # canvas.after(1000,swap_two_pos(barList[pos],barList[pos-1]))
            pos -= 1

        lengthList[pos] = cursor
        barList[pos] = cursorBar
    refresh()
        # swap_two_pos(barList[pos],cursorBar)

def refresh():
    canvas.delete('all')
    xstart = 5
    xend = 15

    for i, length in enumerate(lengthList): #range(1,60):
        y = random.randint(1,390)
        x = canvas.create_rectangle(xstart,length,xend,395, fill='red')
        barList.append(x)
        xstart += 10
        xend += 10


def shuffle():
    global barList
    global lengthList
    canvas.delete('all')
    xstart = 5
    xend = 15
    barList = []
    lengthList = []

    for x in range(1,60):
        randomY = random.randint(1,390)
        x = canvas.create_rectangle(xstart,randomY,xend,395, fill='red')
        barList.append(x)
        xstart += 10
        xend += 10

    for bar in barList:
        x = canvas.coords(bar)
        length = x[3]-x[1]
        lengthList.append(length)

    for i in range(len(lengthList)-1):
        if lengthList[i] == min(lengthList):
            canvas.itemconfig(barList[i], fill='blue')
        elif lengthList[i] == max(lengthList):
            canvas.itemconfig(barList[i], fill='green')

window = tk.Tk()
window.title('Sorting')
window.geometry('600x435')
canvas = tk.Canvas(window, width='600', height='400')
canvas.grid(column=0,row=0, columnspan = 50)

insert = tk.Button(window, text='Insertion Sort', command=insertion_sort)
shuf = tk.Button(window, text='Shuffle', command=shuffle)
insert.grid(column=1,row=1)
shuf.grid(column=0, row=1)

shuffle()
window.mainloop()