import pygame
import sys
import random
 
SCREEN_X=600
SCREEN_Y=600
 
class Snake(object):
 def __init__(self):
 self.direction=pygame.K_RIGHT
 self.body = []
 for i in range(5):
  self.addnode()
 
 def addnode(self):
 left, top = (0, 0)
 if self.body:
  left, top = (self.body[0].left,self.body[0].top)
 node = pygame.Rect(left,top,25,25)
 if self.direction == pygame.K_RIGHT:
  node.left += 25
 elif self.direction == pygame.K_LEFT:
  node.left -= 25
 elif self.direction == pygame.K_UP:
  node.top -= 25
 elif self.direction == pygame.K_DOWN:
  node.top += 25
 self.body.insert(0,node)
 
 def delnode(self):
 self.body.pop()
 
 def isdead(self):
 if self.body[0].x not in range(SCREEN_X):
  return True
 if self.body[0].y not in range(SCREEN_Y):
  return True
 if self.body[0] in self.body[1:]:
  print('in body')
  return True
 return False
 
 def move(self):
 self.addnode()
 self.delnode()
 
 def changeddirection(self,curkey):
 LR = [pygame.K_LEFT,pygame.K_RIGHT]
 UD = [pygame.K_DOWN,pygame.K_UP]
 if curkey in LR+UD:
  if (curkey in LR) and (self.direction in LR):
  return
  if (curkey in UD) and (self.direction in UD):
  return
  self.direction = curkey
 
class Food(object):
 def __init__(self):
 self.rect = pygame.Rect(-25, 0, 25, 25)
 
 def remove(self):
 self.rect.x = -25
 
 def set(self):
 if self.rect.x == -25:
  allpos = []
  for pos in range(25,SCREEN_X-25,25):
  allpos.append(pos)
  self.rect.left = random.choice(allpos)
  self.rect.top = random.choice(allpos)
  print(self.rect)
 
def show_text(screen,pos,text,color,font_bold = False,font_size = 60,font_italic = False):
 cur_font=pygame.font.SysFont('宋体',font_size)
 cur_font.set_bold(font_bold)
 cur_font.set_italic(font_italic)
 text_fmt = cur_font.render(text,1,color)
 screen.blit(text_fmt,pos)
 
def main():
 pygame.init()
 screen_size = (SCREEN_X,SCREEN_Y)
 screen = pygame.display.set_mode(screen_size)
 pygame.display.set_caption('Snake')
 clock=pygame.time.Clock()
 scores=0
 isdead=False
 
 snake=Snake()
 food=Food()
 
 while True:
 for event in pygame.event.get():
 
  if event.type == pygame.QUIT:
  sys.exit()
  if event.type == pygame.KEYDOWN:
  #print(event)
  #pressed_keys = pygame.key.get_pressed()
  #if pressed_keys.count(1)>1:
   # continue
  print(event.key)
  snake.changeddirection(event.key)
  if event.key == pygame.K_SPACE and isdead:
   return main()
 screen.fill((255,255,255))
 if not isdead:
  scores +=1
  snake.move()
 for rect in snake.body:
  pygame.draw.rect(screen,(20,220,39),rect,0)
 isdead=snake.isdead()
 if isdead:
  show_text(screen,(100,200),'you dead!',(227,29,18),False,100)
  show_text(screen,(150,260),'press space to try again...',(0,0,22),False,30)
 
 if food.rect == snake.body[0]:
  scores +=50
  food.remove()
  snake.addnode()
 
 food.set()
 pygame.draw.rect(screen,(136,0,21),food.rect,0)
 show_text(screen,(50,500),'Scores:'+str(scores),(223,223,223))
 pygame.display.update()
 clock.tick(5)
 
if __name__ == "__main__":
 main()