Timer Turtle

import turtle
import time

screen = turtle.Screen()
screen.title("Секундомер")

elapsed = 0.0
running = False
last_update = 0.0

display = turtle.Turtle()
display.hideturtle()
display.penup()
display.goto(0, 50)

def format_time(t):
    h = int(t // 3600)
    m = int((t % 3600) // 60)
    s = int(t % 60)
    return f"{h:02d}:{m:02d}:{s:02d}"

def update_clock():
    global elapsed, last_update
    if running:
        now = time.time()
        elapsed += now - last_update
        last_update = now
        display.clear()
        display.write(format_time(elapsed), align="center", font=("Arial", 24, "normal"))
    screen.ontimer(update_clock, 100)

def start(x=None, y=None):
    global running, last_update
    if not running:
        running = True
        last_update = time.time()
        update_clock()

def pause(x=None, y=None):
    global running, elapsed
    if running:
        running = False
        display.clear()
        display.write(format_time(elapsed), align="center", font=("Arial", 24, "normal"))

def stop(x=None, y=None):
    global running, elapsed
    running = False
    elapsed = 0.0
    display.clear()
    display.write(format_time(elapsed), align="center", font=("Arial", 24, "normal"))

def make_button(label, pos, callback):
    btn = turtle.Turtle()
    btn.hideturtle()
    btn.penup()
    btn.shape("square")
    btn.shapesize(stretch_wid=1, stretch_len=4)
    btn.fillcolor("lightgray")
    btn.goto(pos)
    btn.showturtle()
    btn.write(label, align="center", font=("Arial", 12, "normal"))
    btn.onclick(callback)
    return btn

make_button("START", (-100, -50), start)
make_button("PAUSE", (0, -50), pause)
make_button("STOP", (100, -50), stop)

display.write("00:00:00", align="center", font=("Arial", 24, "normal"))

screen.mainloop()