从这里“You can do the steps from
Flak‘s answer, or you can simply
download the Windows installer, double click to launch it, and be on your way”.
下载了lxml2.7对应的whl;
pip install wheel;安装工具wheel以安装lxml.xxxx.whl安装包；
wheel install lxml.xxxx.whl;
set STATICBUILD=true && pip install lxml；
（ok,终于把lxml安装好了）
