save project

snake.py

@@ -49,6 +49,8 @@ while True:
         y -= 30
     else:
         y += 30  
+    if x < 0 or x > 630 or y<0 or y>450:
+        exit()
     position.append((x, y))
     if ax==x and ay ==y:
        ay=30*random.randint(0,15)
@@ -70,4 +72,5 @@ while True:
     screen.blit(food, (ax,ay))
     # 刷新画面
     pygame.display.update()
-    FPSCLOCK.tick(10)
\ No newline at end of file
+    FPSCLOCK.tick(10)
+    
\ No newline at end of file