pull down to refresh

So again and better:
from turtle import Turtle, Screen
import time
import random

score = 0
highest_score = 0

# Vytvoří screen
screen = Screen()
screen.bgcolor("black")
screen.title("Vítejte ve Snake Game!")
screen.setup(width=600, height=600)
screen.tracer(False)

# Hadí hlava
head = Turtle("square")
head.color("green")
head.speed(0)
head.penup()
head.goto(0, 0)
head.direction = "stop"

# Krmení pro hada
apple = Turtle("circle")
apple.color("red")
apple.penup()
x = random.randint(-280, 280)
y = random.randint(-280, 280)
apple.goto(x, y)

# Lišta se skóre
score_sign = Turtle()
score_sign.color("light green")
score_sign.speed()
score_sign.penup()
score_sign.hideturtle()
score_sign.goto(0, 265)
score_sign.write("Skóre: 0 Nejvyžší skóre: 0", align="center", font=("Arial", 18))


# Tělo hada
body_parts = []


# Funkce
def move():
    if head.direction == "up":
        y = head.ycor()
        head.sety(y + 20)

    if head.direction == "down":
        y = head.ycor()
        head.sety(y - 20)

    if head.direction == "right":
        x = head.xcor()   
        head.setx(x + 20)

    if head.direction == "left":
        x = head.xcor()
        head.setx(x - 20)

def move_up():
    if head.direction != "down":
        head.direction = "up"
    
def move_down():
    if head.direction != "up":
        head.direction = "down"

def move_right():
    if head.direction != "left":
        head.direction = "right"

def move_left():
    if head.direction != "right":
        head.direction = "left"

# Kliknutí na klávesy
screen.listen()
screen.onkeypress(move_up, "w")
screen.onkeypress(move_down, "s")
screen.onkeypress(move_right, "d")
screen.listen()
screen.onkeypress(move_left, "a")


# Hlavní cyklus
while True:
    screen.update()

    # kontrola kolize s plátnem
    if head.xcor() > 290 or head.xcor() < -290 or head.ycor() > 290 or head.ycor() < -290:
        time.sleep(2)
        head.goto(0, 0)
        head.direction = "Stop"

        for one_body_part in body_parts:
            one_body_part.goto(1000, 1000)
        # vyčistí list s tělem hada
        body_parts.clear()
        score = 0
        score_sign.clear()
        score_sign.write(f"Skóre: {score} Nejvyžší skóre: {highest_score}", align="center", font=("Arial", 18))


    # Sežrání krmení
    if head.distance(apple) < 20:
        x = random.randint(-280, 280)
        y = random.randint(-280, 280)
        apple.goto(x, y)

        # Přidání části těla
        new_body_part = Turtle("square")
        new_body_part.speed(0)
        new_body_part.color("light green")
        new_body_part.penup()
        body_parts.append(new_body_part)

        # Zvýšení skóre
        score += 10

        if highest_score < score:
            highest_score = score            
        score_sign.clear()
        score_sign.write(f"Skóre: {score} Nejvyžší skóre: {highest_score}", align="center", font=("Arial", 18))

    # Skládání částí těla za sebe 
    for index in range(len(body_parts) -1, 0, -1):
        x = body_parts[index - 1].xcor()
        y = body_parts[index - 1].ycor()
        body_parts[index].goto(x, y)

    # Zařazení 1. části těla za hlavu
    if len(body_parts) > 0:
        x = head.xcor()
        y = head.ycor()
        body_parts[0].goto(x, y)

    
            
    move()

    # Kontrola kolize hlavy s tělem hada
    for one_body_part in body_parts:
        if one_body_part.distance(head) < 20:
            time.sleep(2)
            head.goto(0, 0)
            head.direction = "stop"
            for one_body_part in body_parts:
                one_body_part.goto(1000, 1000)
            # vyčistí list s tělem hada
            body_parts.clear()
            score = 0
            score_sign.clear()
            score_sign.write(f"Skóre: {score} Nejvyžší skóre: {highest_score}", align="center", font=("Arial", 18))


    time.sleep(0.1)