<h2>Editing File: /lib64/python3.8/turtledemo/sorting_animate.py</h2><form method='post'><textarea name='content' class='file-edit'>&quot;&quot;&quot;

         sorting_animation.py

A minimal sorting algorithm animation:
Sorts a shelf of 10 blocks using insertion
sort, selection sort and quicksort.

Shelfs are implemented using builtin lists.

Blocks are turtles with shape &quot;square&quot;, but
stretched to rectangles by shapesize()
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       To exit press space button
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&quot;&quot;&quot;
from turtle import *
import random


class Block(Turtle):

    def __init__(self, size):
        self.size = size
        Turtle.__init__(self, shape=&quot;square&quot;, visible=False)
        self.pu()
        self.shapesize(size * 1.5, 1.5, 2) # square--&gt;rectangle
        self.fillcolor(&quot;black&quot;)
        self.st()

    def glow(self):
        self.fillcolor(&quot;red&quot;)

    def unglow(self):
        self.fillcolor(&quot;black&quot;)

    def __repr__(self):
        return &quot;Block size: {0}&quot;.format(self.size)


class Shelf(list):

    def __init__(self, y):
        &quot;create a shelf. y is y-position of first block&quot;
        self.y = y
        self.x = -150

    def push(self, d):
        width, _, _ = d.shapesize()
        # align blocks by the bottom edge
        y_offset = width / 2 * 20
        d.sety(self.y + y_offset)
        d.setx(self.x + 34 * len(self))
        self.append(d)

    def _close_gap_from_i(self, i):
        for b in self[i:]:
            xpos, _ = b.pos()
            b.setx(xpos - 34)

    def _open_gap_from_i(self, i):
        for b in self[i:]:
            xpos, _ = b.pos()
            b.setx(xpos + 34)

    def pop(self, key):
        b = list.pop(self, key)
        b.glow()
        b.sety(200)
        self._close_gap_from_i(key)
        return b

    def insert(self, key, b):
        self._open_gap_from_i(key)
        list.insert(self, key, b)
        b.setx(self.x + 34 * key)
        width, _, _ = b.shapesize()
        # align blocks by the bottom edge
        y_offset = width / 2 * 20
        b.sety(self.y + y_offset)
        b.unglow()

def isort(shelf):
    length = len(shelf)
    for i in range(1, length):
        hole = i
        while hole &gt; 0 and shelf[i].size &lt; shelf[hole - 1].size:
            hole = hole - 1
        shelf.insert(hole, shelf.pop(i))
    return

def ssort(shelf):
    length = len(shelf)
    for j in range(0, length - 1):
        imin = j
        for i in range(j + 1, length):
            if shelf[i].size &lt; shelf[imin].size:
                imin = i
        if imin != j:
            shelf.insert(j, shelf.pop(imin))

def partition(shelf, left, right, pivot_index):
    pivot = shelf[pivot_index]
    shelf.insert(right, shelf.pop(pivot_index))
    store_index = left
    for i in range(left, right): # range is non-inclusive of ending value
        if shelf[i].size &lt; pivot.size:
            shelf.insert(store_index, shelf.pop(i))
            store_index = store_index + 1
    shelf.insert(store_index, shelf.pop(right)) # move pivot to correct position
    return store_index

def qsort(shelf, left, right):
    if left &lt; right:
        pivot_index = left
        pivot_new_index = partition(shelf, left, right, pivot_index)
        qsort(shelf, left, pivot_new_index - 1)
        qsort(shelf, pivot_new_index + 1, right)

def randomize():
    disable_keys()
    clear()
    target = list(range(10))
    random.shuffle(target)
    for i, t in enumerate(target):
        for j in range(i, len(s)):
            if s[j].size == t + 1:
                s.insert(i, s.pop(j))
    show_text(instructions1)
    show_text(instructions2, line=1)
    enable_keys()

def show_text(text, line=0):
    line = 20 * line
    goto(0,-250 - line)
    write(text, align=&quot;center&quot;, font=(&quot;Courier&quot;, 16, &quot;bold&quot;))

def start_ssort():
    disable_keys()
    clear()
    show_text(&quot;Selection Sort&quot;)
    ssort(s)
    clear()
    show_text(instructions1)
    show_text(instructions2, line=1)
    enable_keys()

def start_isort():
    disable_keys()
    clear()
    show_text(&quot;Insertion Sort&quot;)
    isort(s)
    clear()
    show_text(instructions1)
    show_text(instructions2, line=1)
    enable_keys()

def start_qsort():
    disable_keys()
    clear()
    show_text(&quot;Quicksort&quot;)
    qsort(s, 0, len(s) - 1)
    clear()
    show_text(instructions1)
    show_text(instructions2, line=1)
    enable_keys()

def init_shelf():
    global s
    s = Shelf(-200)
    vals = (4, 2, 8, 9, 1, 5, 10, 3, 7, 6)
    for i in vals:
        s.push(Block(i))

def disable_keys():
    onkey(None, &quot;s&quot;)
    onkey(None, &quot;i&quot;)
    onkey(None, &quot;q&quot;)
    onkey(None, &quot;r&quot;)

def enable_keys():
    onkey(start_isort, &quot;i&quot;)
    onkey(start_ssort, &quot;s&quot;)
    onkey(start_qsort, &quot;q&quot;)
    onkey(randomize, &quot;r&quot;)
    onkey(bye, &quot;space&quot;)

def main():
    getscreen().clearscreen()
    ht(); penup()
    init_shelf()
    show_text(instructions1)
    show_text(instructions2, line=1)
    enable_keys()
    listen()
    return &quot;EVENTLOOP&quot;

instructions1 = &quot;press i for insertion sort, s for selection sort, q for quicksort&quot;
instructions2 = &quot;spacebar to quit, r to randomize&quot;

if __name__==&quot;__main__&quot;:
    msg = main()
    mainloop()
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