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