SCREEN_X = 500
SCREEN_Y = 500
screen_size = (SCREEN_X, SCREEN_Y)
screen = pygame.display.set_mode(screen_size)
pygame.display.set_caption('贪吃蛇')

def __init__(self):
 self.dirction = pygame.K_RIGHT
 self.body = []

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, 20, 20)
 if self.dirction == pygame.K_LEFT:
 node.left -= 20
 elif self.dirction == pygame.K_RIGHT:
 node.left += 20
 elif self.dirction == pygame.K_UP:
 node.top -= 20
 elif self.dirction == pygame.K_DOWN:
 node.top += 20
 self.body.insert(0, node)

def delNode(self):
 self.body.pop()

def changeDirection(self, curkey):
 LR = [pygame.K_LEFT, pygame.K_RIGHT]
 UD = [pygame.K_UP, pygame.K_DOWN]
 if curkey in LR + UD:
 if (curkey in LR) and (self.dirction in LR):
  return
 if (curkey in UD) and (self.dirction in UD):
  return
 self.dirction = curkey

def isDead(self):
 # 撞墙
 if self.body[0].x not in range(SCREEN_X):
 return True
 if self.body[0].y not in range(SCREEN_Y):
 return True
 # 撞自己
 if self.body[0] in self.body[1:]:
 return True
 return False

def set(self):
 if self.rect.x == -20:
 allpos = []
 for pos in range(20, SCREEN_X - 20, 20):
  allpos.append(pos)
 self.rect.left = random.choice(allpos)
 self.rect.top = random.choice(allpos)
 print(self.rect)

def remove(self):
 self.rect.x = -20

def show_text(screen, pos, text, color, font_bold=False, font_size=30, font_italic=False):
 # 设置文字大小
 cur_font = pygame.font.SysFont("宋体", font_size)
 # 加粗
 cur_font.set_bold(font_bold)
 # 斜体
 cur_font.set_italic(font_italic)
 # 设置内容
 text_fmt = cur_font.render(text, 1, color)
 # 绘制文字
 screen.blit(text_fmt, pos)

show_text(screen, (50, 400), 'scores: ' + str(scores), (103, 213, 213))

show_text(screen, (150, 50), 'GAME OVER', (227, 29, 18), False, 50)
show_text(screen, (140, 100), "Press space to try again", (0, 0, 22), False, 30)

if food.rect == snake.body[0]:
 scores += 1
 food.remove()
 snake.addNode()

# 投放食物
food.set()