save project

snake.py

@@ -59,6 +59,9 @@ while True:
         apple_y=random.randint(1,16)*30-30
     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
@@ -75,4 +78,4 @@ while True:
     screen.blit(food, (apple_x, apple_y))
     # 刷新画面
     pygame.display.update()
-    FPSCLOCK.tick(3)
\ No newline at end of file
+    FPSCLOCK.tick(10)
\ No newline at end of file