save project

snake.py

@@ -60,8 +60,11 @@ while True:
         num2 = random.randint(1,16)
         apple_x =num1*30-30
         apple_y =num2*30-30
+        score += 10
     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