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snake.py

@@ -64,6 +64,9 @@ while True:
         score=score+1
     else:
         position.pop(0)
+        
+    if x<0 or x>450 or y>630 or y<0:
+        exit()
     # 将背景图画上去
     screen.blit(background, (0, 0))
     # 将贪吃蛇的头画上去