Classic Snake Game

Snake.py

import pygame
import random
import sys
from pygame.locals import *
def collide(x1,x2,y1,y2,wh):
	w1=20;
	w2=wh;
	h2=wh;
	h1=20;
	if x1+w1>x2 and x1<x2+w2 and y1+h1>y2 and y1<y2+h2:
		return True
	else:
		return False
def die(screen, score):
	f=pygame.font.SysFont('Monospace',30);
	t=f.render('YOUR SCORE IS : '+str(score),True,(0,0,0));
	screen.blit(t,(10,270));
	pygame.display.update();
	pygame.time.wait(2000);
	sys.exit(0)
xs=[290,290,290,290,290];
ys=[290,270,250,230,210];
dirs=0;
score=0;
applepos=(random.randint(0,590),random.randint(0,590));
pygame.init();
s=pygame.display.set_mode((600,600));
pygame.display.set_caption('SNAKE');
appleimage=pygame.Surface((10,10));
appleimage.fill((0,255,0));
img=pygame.Surface((20,20));
img.fill((255,0,0));
f=pygame.font.SysFont('Monospace',20);
clock=pygame.time.Clock()
while True:
	clock.tick(10)
	for e in pygame.event.get():
		if e.type==QUIT:
			sys.exit(0)
		elif e.type==KEYDOWN:
			if e.key==K_UP and dirs!=0:
				dirs=2
			elif e.key==K_DOWN and dirs!=2:
				dirs=0
			elif e.key==K_LEFT and dirs!=1:
				dirs=3
			elif e.key==K_RIGHT and dirs!=3:
				dirs=1
	i=len(xs)-1
	while i>=2:
		if collide(xs[0],xs[i],ys[0],ys[i],20):
			die(s,score)
		i-=1
	if collide(xs[0],applepos[0],ys[0],applepos[1],10):
		score+=1;
		xs.append(700);
		ys.append(700);
		applepos=(random.randint(0,590),random.randint(0,590))
	if xs[0] < 0 or xs[0] > 580 or ys[0] < 0 or ys[0] > 580:
		die(s,score)
	i=len(xs)-1
	while i >= 1:
		xs[i]=xs[i-1];
		ys[i]=ys[i-1];
		i-=1
	if dirs==0:
		ys[0]+=20
	elif dirs==1:
		xs[0]+=20
	elif dirs==2:
		ys[0]-=20
	elif dirs==3:
		xs[0]-=20	
	s.fill((255,255,255))	
	for i in range(0,len(xs)):
		s.blit(img,(xs[i],ys[i]))
	s.blit(appleimage,applepos);
	t=f.render(str(score),True,(0,0,0));
	s.blit(t,(10,10));
	pygame.display.update()