How do I correctly implement a bubble sort algorithm in python tkinter?

The biggest problem is that inside sort_two you have if

if y2 > y1:    canvas.move(pos_0, x_10-x_00, 0)    canvas.move(pos_1, x_01-x_11, 0)

which replaces elements only if y2 > y1

but after sort_two() you use barList

sort_two(pos_1, pos_2)barList[rd1], barList[rd2] = barList[rd2], barList[rd1]

which always replaces elements on list.

And this way you have wrong results on screen.

You could return True/False from sort_two() to control when to change elements on barList

if y2 > y1:    canvas.move(pos_0, x_10-x_00, 0)    canvas.move(pos_1, x_01-x_11, 0)    return Trueelse:    return False

and

if sort_two(pos_1, pos_2):    barList[rd1], barList[rd2] = barList[rd2], barList[rd1]

Here finall code

I use simple calculation for replacing elements on canvas

x1, _, _, _ = canvas.coords(pos_0)x2, _, _, _ = canvas.coords(pos_1)diff = x1 - x2canvas.move(pos_0, -diff, 0)canvas.move(pos_1, +diff, 0)

I also removed

 else:    break

which stop animation after every replace and it needs to click button sort again and again - and I use

    window.update()    time.sleep(0.1)

so it displays animation (slowly) to the end of sorting and I don't have to click button sort

import tkinter as tkimport randomimport timedef swap_two_pos(pos_0, pos_1):    """This does the graphical swapping of the rectangles on the canvas    by moving one rectangle to the location of the other, and vice versa    """            x1, _, _, _ = canvas.coords(pos_0)    x2, _, _, _ = canvas.coords(pos_1)        diff = x1 - x2    canvas.move(pos_0, -diff, 0)    canvas.move(pos_1, +diff, 0)def sort_two(pos_0, pos_1):    x1, y1, _, _ = canvas.coords(pos_0)    x2, y2, _, _ = canvas.coords(pos_1)    diff = x1 - x2    # moves each rectangle to the x position of the other; y remains unchanged    if y2 > y1:        canvas.move(pos_0, -diff, 0)        canvas.move(pos_1, +diff, 0)        return True    else:        return Falsedef rand_sort():    for i in range(50000):        rd1 = random.randint(0, 58)        rd2 = random.randint(0, 58)        pos_1 = barList[rd1]        pos_2 = barList[rd2]        if sort_two(pos_1, pos_2):            barList[rd1], barList[rd2] = barList[rd2], barList[rd1]def sort ():    n = len(barList)      # Traverse through all array elements     for i in range(n):           # Last i elements are already in place         for j in range(0, n-i-1):            if sort_two(barList[j], barList[j+1]):                barList[j], barList[j+1] = barList[j+1], barList[j]                    window.update()        time.sleep(0.1)                def random_swap():    """Not a sort yet, but you have the bare bones operations    so the swap is executed    """    for i in range(500):        rd1 = random.randint(0, 58)        rd2 = random.randint(0, 58)        pos_0 = barList[rd1]        pos_1 = barList[rd2]                swap_two_pos(pos_0, pos_1)        # it is necessary to swap the values in the list too        barList[rd1], barList[rd2] = barList[rd2], barList[rd1]window = tk.Tk()window.title('Sorting')window.geometry('600x400')# button to command the swaptk.Button(window, text='swap', command=random_swap).pack()tk.Button(window, text='sort', command=sort).pack()xstart = 5xend = 15canvas = tk.Canvas(window, width='900', height='900')canvas.pack()barList = []lengthList = []Y = 5for x in range(1,60):    bar = canvas.create_rectangle(xstart, Y, xend, 395, fill='red')    barList.append(bar)    xstart += 10    xend += 10    Y += 5for bar in barList:    x = canvas.coords(bar)    length = x[3]-x[1]    lengthList.append(length)window.mainloop()