save project

snake.py

 import pygame
 from pygame import locals
-
+import random
 # 初始化pygame，为使用硬件做准备
 pygame.init()
 
@@ -57,11 +57,16 @@ while True:
     position.append((x, y))
 
     if x == apple_x and y == apple_y:
+        score+=1
         num1 = random.randint(1, 22)
         num2 = random.randint(1, 16)
         apple_x = 30*num1-30
         apple_y = 30*num2-30
+    else:
         position.pop(0)
+
+    if x < 0 or x > 630 or y < 0 or y > 450:
+        exit()
     # 将背景图画上去
     screen.blit(background, (0, 0))
     # 将贪吃蛇的头画上去