save project

snake.py

@@ -61,7 +61,8 @@ while True:
         score += 10
     else:      
         position.pop(0)
-    if x < 0 or x > 630 or y < 0 or y > 450 
+    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