python在windows平台的pip安装package时的编译问题

在安装pcapy时，出现以下错误：

building 'pcapy' extension
error: Microsoft Visual C++ 9.0 is required (Unable to find vcvarsall.bat). Get it from http://aka.ms/vcpython27

原来这世界上有个东西叫： 

Microsoft Visual C++ Compiler for Python 2.7