Failed building wheel for Twisted

在安装scrapy框架的过程中，pip install scrapy 出现报错信息：

building 'twisted.test.raiser' extension
error: Microsoft Visual C++ 14.0 is required. Get it with "Microsoft Visual C++ Build Tools": http://landinghub.visualstudio.com/visual-cpp-build-tools

解决方法：

网址：https://www.lfd.uci.edu/~gohlke/pythonlibs/#twisted

选择 与自己电脑python版本相关的Twisted。下载保存到本地。

• Twisted‑17.9.0‑cp36‑cp36m‑win_amd64.whl    amd64：表示64位，36表示python3.6版本。

　　然后执行pip install xx\xx\Twisted‑17.9.0‑cp36‑cp36m‑win_amd64.whl

　　执行结果如图所示：

(jobbole) D:\virtualenv>pip install D:\virtualenv\jobbole\Scripts\Twisted-17.9.-cp36-cp36m-win_amd64.whl
Processing d:\virtualenv\jobbole\scripts\twisted-17.9.-cp36-cp36m-win_amd64.whl
Requirement already satisfied: incremental>=16.10. in d:\virtualenv\jobbole\lib\site-packages (from Twisted==17.9.)
Requirement already satisfied: zope.interface>=4.0. in d:\virtualenv\jobbole\lib\site-packages (from Twisted==17.9.)
Requirement already satisfied: Automat>=0.3. in d:\virtualenv\jobbole\lib\site-packages (from Twisted==17.9.)
Requirement already satisfied: constantly>=15.1 in d:\virtualenv\jobbole\lib\site-packages (from Twisted==17.9.)
Requirement already satisfied: hyperlink>=17.1. in d:\virtualenv\jobbole\lib\site-packages (from Twisted==17.9.)
Requirement already satisfied: setuptools in d:\virtualenv\jobbole\lib\site-packages (from zope.interface>=4.0.->Twisted==17.9.)
Requirement already satisfied: six in d:\virtualenv\jobbole\lib\site-packages (from Automat>=0.3.->Twisted==17.9.)
Requirement already satisfied: attrs in d:\virtualenv\jobbole\lib\site-packages (from Automat>=0.3.->Twisted==17.9.)
Requirement already satisfied: idna>=2.5 in d:\virtualenv\jobbole\lib\site-packages (from hyperlink>=17.1.->Twisted==17.9.)
Installing collected packages: Twisted
Successfully installed Twisted-17.9.

　　然后，顺利安装scrapy

(jobbole) D:\virtualenv>pip install scrapy