Snake

import pygame, sys, random
from pygame.locals import *
pygame.init()
pygame.display.set_caption('Snake')
clock = pygame.time.Clock()
screen  = pygame.display.set_mode((500, 500))
snake = [[25,25],[26,25],[27,25],[28,25]]
appleX,appleY = 10,10
dirx,diry = -1,0
grid  = 10
body = pygame.Surface((grid,grid))
body.fill((0,255,0))
apple = pygame.Surface((grid,grid))
apple.fill((255,0,0))

def checkOverlap():
    for x,y in snake[3:]:
        if snake[0][0] == x and snake[0][1] == y: endgame()

def checkAppleHit():
    global appleX, appleY
    if snake[0][0] == appleX and snake[0][1] == appleY:
        appleX,appleY = random.randrange(2,48),random.randrange(2,48) #Plasser nytt eple
        snake.insert(1,[snake[1][0],snake[1][1]]) #Doble ledd nr 2

def endgame():
    pygame.quit()
    sys.exit()

while True:
    screen.fill((255,255,255))
    snake.pop(-1) #Fjerner siste del av halen
    snake.insert(0,[snake[0][0]+dirx,snake[0][1]+diry]) #Legger til en ny del først i den retningen slangen beveger seg.
    screen.blit(apple, (appleX*grid,appleY*grid))
    for x,y in snake:
        screen.blit(body, (x*grid, y*grid))
    checkAppleHit()
    checkOverlap()
    for event in pygame.event.get():
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_LEFT and not dirx == 1: dirx,diry = -1,0
            if event.key == pygame.K_RIGHT and not dirx == -1: dirx,diry = 1,0
            if event.key == pygame.K_UP and not diry == 1: dirx,diry = 0,-1
            if event.key == pygame.K_DOWN and not diry == -1: dirx,diry = 0,1
        if event.type == QUIT: endgame()
    pygame.display.update()
    clock.tick(8)