我已经安装了 html5lib 包。我敢肯定，因为当我尝试安装它时，我会收到一条消息，指出它已安装。
pip install html5lib
Requirement already satisfied: html5lib in ./anaconda/lib/python3.5/site-packages
我也能够成功导入该包。
import html5lib
然而，当我尝试将解析器用作 BeautifulSoup 构造函数的一部分时
soup = BeautifulSoup(response.data, 'html5lib')
我不成功
FeatureNotFound: Couldn't find a tree builder with the features you requested: html5lib. Do you need to install a parser library?
是否可以强制 bs4 查找已安装的解析器并成功找到 html5lib？