Couldn't find a tree builder with the features you requested: lxml. Do you need to install a parser library?

python3.6.3 

我在处理爬虫时候使用BeautifulSoup中遇到报错

“ bs4.FeatureNotFound: Couldn't find a tree builder with the features you requested: lxml. Do you need to install a parser library?  ”

在查阅资料中偶遇一种简单的解决方式：把代码中的'lxml'改成'html.parser'后成功解决。