出错点

1、High order functions calculate letter case

Using the addition between strings

2、iterable Object needs to convert (list) output  

map-->map object (list or tuple(map))

range() -->range (list or tuple(range))

fiter()------>fiter object (list or tuple(fiter))

 (i for ...) ---> generater  object (list or tuple())

出错点

原文：https://www.cnblogs.com/yhmdj/p/14433957.html