save project

snake.py

@@ -59,7 +59,8 @@ while True:
        num2 = random.randint(1,16)
        apple_x = num1*30-30
        apple_y = num2*30-30
-    position.pop(0)
+    else:
+        position.pop(0)
     # 将背景图画上去
     screen.blit(background, (0, 0))
     # 将贪吃蛇的头画上去