环境：Win10 64位，Python版本 3.6
在CMD命令行用 pip.exe install pycrypto 安装PyCrypto模块时报错：
error: Microsoft Visual C++ 14.0 is required. Get it with "Microsoft Visual C++ Build Tools": http://landinghub.visualstudio.com/visual-cpp-build-tools
这是因为pycrypto模块编译需要依赖Visual C++ 14.0的编译工具，网上搜了一些方案，发现很多人遇到这个问题。自己也实践了下，踩过一些坑，总结的解决方案如下：
1. 安装Visual Studio 2015。
下载地址在https://pan.baidu.com/s/1WaBxFghTll6Zofz1DGOZBg。
等待漫长的安装过程安装完成。。。
安装完成后，再用pip安装，会报错如下：
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt\inttypes.h(26): error C2061: syntax error: identifier 'intmax_t'
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt\inttypes.h(27): error C2061: syntax error: identifier 'rem'
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt\inttypes.h(27): error C2059: syntax error: ';'
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt\inttypes.h(28): error C2059: syntax error: '}'
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt\inttypes.h(30): error C2061: syntax error: identifier 'imaxdiv_t'
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt\inttypes.h(30): error C2059: syntax error: ';'
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt\inttypes.h(40): error C2143: syntax error: missing '{' before '__cdecl'
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt\inttypes.h(41): error C2146: syntax error: missing ')' before identifier '_Number'
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt\inttypes.h(41): error C2061: syntax error: identifier '_Number'
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt\inttypes.h(41): error C2059: syntax error: ';'
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt\inttypes.h(42): error C2059: syntax error: ')'
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt\inttypes.h(45): error C2143: syntax error: missing '{' before '__cdecl'
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt\inttypes.h(46): error C2146: syntax error: missing ')' before identifier '_Numerator'
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt\inttypes.h(46): error C2061: syntax error: identifier '_Numerator'
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt\inttypes.h(46): error C2059: syntax error: ';'
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt\inttypes.h(46): error C2059: syntax error: ','
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt\inttypes.h(48): error C2059: syntax error: ')'
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt\inttypes.h(50): error C2143: syntax error: missing '{' before '__cdecl'
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt\inttypes.h(56): error C2143: syntax error: missing '{' before '__cdecl'
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt\inttypes.h(63): error C2143: syntax error: missing '{' before '__cdecl'
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt\inttypes.h(69): error C2143: syntax error: missing '{' before '__cdecl'
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt\inttypes.h(76): error C2143: syntax error: missing '{' before '__cdecl'
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt\inttypes.h(82): error C2143: syntax error: missing '{' before '__cdecl'
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt\inttypes.h(89): error C2143: syntax error: missing '{' before '__cdecl'
C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt\inttypes.h(95): error C2143: syntax error: missing '{' before '__cdecl'
error: command 'D:\\Program Files (x86)\\Microsoft Visual Studio 14.0\\VC\\BIN\\cl.exe' failed with exit status 2
这时按第2步操作。
方法一：
2. 设置环境变量“VCINSTALLDIR”值为VC的安装路径，我的是“D:\Program Files (x86)\Microsoft Visual Studio 14.0\VC”（Visual Studio 2015安装界面默认VC是安装在C盘，可以修改安装在D盘！）。
3. 重新打开CMD，键入set CL=/FI"%VCINSTALLDIR%\\INCLUDE\\stdint.h" 。再用pip安装就可以成功。
4. 如果修改路径还报cl.exe缺失的错误，那么就用第二种方法
方法二：
网站上所写的解决方法为：
Open Visual C++ 2015 x86 x64 Cross Build Tools Command Prompt--> change directory cd C:\Users\Test\AppData\Local\Programs\Python\Python36-32\Scripts-->Type: pip install package_name依据我的系统最后为
打开：Visual C++ 2015 x86 x64 Cross Build Tools Command Prompt
然后：进入我的python3目录的scripts中
最后：执行pip install wordcloud
（注意：不要把“Visual C++ 2015 x86 x64 Cross Build Tools Command Prompt”和“Visual C++ 2015 x64 x86 cross Build Tools Command Prompt“搞错了，两个名字很像，我一开始就用错了也会报错！）
注：在实践过程中，发现pip有可能报 UnicodeDecodeError: 'utf-8' codec can't decode byte... 错误，这时需要将CMD的终端编码用“CHCP 65001”命令改为“UTF-8”后再安装。
附加：https://www.lfd.uci.edu/~gohlke/pythonlibs/#lxml 这个网址里面有很多需要用上的python包，需要的自取~