save project

snake.py

@@ -59,7 +59,8 @@ while True:
         num_y=randint(0,15)
         num_y=randint(0,15)
         food_x=num_x*30
         food_x=num_x*30
         food_y=num_y*30
         food_y=num_y*30
-    position.pop(0)
+    else:
+        position.pop(0)
     # 将背景图画上去
     # 将背景图画上去
     screen.blit(background, (0, 0))
     screen.blit(background, (0, 0))
     # 将贪吃蛇的头画上去
     # 将贪吃蛇的头画上去