貌似缺啥子东西。。。

/Users/Yvan/PycharmProjects/untitled1/baike_spider/spider_main.py 正在爬取第1个URL:http://baike.baidu.com/view/21087.html Couldn't find a tree builder with the features you requested: html_parser. Do you need to install a parser library? craw faild 就我一个人遇到这个情况吗