不怕贼偷，就怕贼惦记！

传说有个R，R里有个包，包的名字叫praise，会一直不停地夸赞你。

> praise()
[1] "You are sensational!"
> praise()
[1] "You are luminous!"
> praise()
[1] "You are pioneering!"
> praise()
[1] "You are riveting!"
> praise()
[1] "You are neat!"
> praise()
[1] "You are supreme!"
> praise()
[1] "You are classy!"
> praise()
[1] "You are sensational!"
> praise()
[1] "You are peachy!"

换种方式

> praise("${EXCLAMATION}! You have done this ${adverb_manner}!")
[1] "WOWIE! You have done this politely!"> praise("${EXCLAMATION}! You have done this ${adverb_manner}!")
[1] "HURRAH! You have done this gracefully!"> praise("${EXCLAMATION}! You have done this ${adverb_manner}!")
[1] "AHHH! You have done this fondly!"

回想刚学R的时候，总记不住，偶然发现有CheetSheet，就打印出来。听讲座时带着，没睡着时看一下；平常遇到问题也看一下。简单几页，提供了很大帮助，后来翻烂了，也就忘记这个东西了。

今天突然想起，搜索了下，又找到了这些密密麻麻的小字，找回我们的过去，分享与此。大部分要学的东西都会有类似的CheetSheet，刚学时，拿过来多看看，越看越熟，也就多会一些了。

学习靠的就是不断反复！不要指望一遍记不住，也不要以为十遍会没效果！惦记是个好东西。