Windows 10家庭中文版，Python 3.6.4，

180824测试前端加密文本在后台揭秘，查询后发现，可以使用pycrypto模块实现，那么，安装它（pip），结果安装失败了。

本文暂时记录下失败的日志，后面找到解决问题了再完善博文。

pycrypto相关网址：

PyPI：https://pypi.org/project/pycrypto/

官网：https://www.dlitz.net/software/pycrypto/

官文：https://www.dlitz.net/software/pycrypto/api/current/

使用pip list，没有找到pycrypto，那么，安装它。

>pip3 install pycrypto

下面是安装过程日志中的部分错误信息：

...

Running setup.py bdist_wheel for pycrypto ... error
Complete output from command c:\python36\python3.exe -u -c "import setuptools, tokenize;__file__='C:\\Users\\log\\AppData\\Local\\Temp\\pip-install-0e9wj35t\\pycrypto\\setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" bdist_wheel -d C:\Users\log\AppData\Local\Temp\pip-wheel-i1adunc1 --python-tag cp36:
...
warning: GMP or MPIR library not found; Not building Crypto.PublicKey._fastmath.
...
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\BIN\x86_amd64\cl.exe /c /nologo /Ox /W3 /GL /DNDEBUG /MD -Isrc/ -Isrc/inc-msvc/ -Ic:\python36\include -Ic:\python36\include "-IC:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\INCLUDE" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt" "-IC:\Program Files (x86)\Windows Kits\8.1\include\shared" "-IC:\Program Files (x86)\Windows Kits\8.1\include\um" "-IC:\Program Files (x86)\Windows Kits\8.1\include\winrt" /Tcsrc/winrand.c /Fobuild\temp.win-amd64-3.6\Release\src/winrand.obj
winrand.c
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(95): error C2143: syntax error: missing '{' before '__cdecl'
error: command 'C:\\Program Files (x86)\\Microsoft Visual Studio 14.0\\VC\\BIN\\x86_amd64\\cl.exe' failed with exit status 2
...
----------------------------------------
Failed building wheel for pycrypto
Running setup.py clean for pycrypto
Failed to build pycrypto
Installing collected packages: pycrypto
Running setup.py install for pycrypto ... error
Complete output from command c:\python36\python3.exe -u -c "import setuptools, tokenize;__file__='C:\\Users\\log\\AppData\\Local\\Temp\\pip-install-0e9wj35t\\pycrypto\\setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record C:\Users\log\AppData\Local\Temp\pip-record-ux9dvuso\install-record.txt --single-version-externally-managed --compile:
running install
...
build\lib.win-amd64-3.6\Crypto\Signature
Skipping optional fixer: buffer
Skipping optional fixer: idioms
Skipping optional fixer: set_literal
Skipping optional fixer: ws_comma
running build_ext
warning: GMP or MPIR library not found; Not building Crypto.PublicKey._fastmath.
building 'Crypto.Random.OSRNG.winrandom' extension
...
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\BIN\x86_amd64\cl.exe /c /nologo /Ox /W3 /GL /DNDEBUG /MD -Isrc/ -Isrc/inc-msvc/ -Ic:\python36\include -Ic:\python36\include "-IC:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\INCLUDE" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt" "-IC:\Program Files (x86)\Windows Kits\8.1\include\shared" "-IC:\Program Files (x86)\Windows Kits\8.1\include\um" "-IC:\Program Files (x86)\Windows Kits\8.1\include\winrt" /Tcsrc/winrand.c /Fobuild\temp.win-amd64-3.6\Release\src/winrand.obj
winrand.c
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: '}'
...
----------------------------------------
Command "c:\python36\python3.exe -u -c "import setuptools, tokenize;__file__='C:\\Users\\log\\AppData\\Local\\Temp\\pip-install-0e9wj35t\\pycrypto\\setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record C:\Users\log\AppData\Local\Temp\pip-record-ux9dvuso\install-record.txt --single-version-externally-managed --compile" failed with error code 1 in C:\Users\log\AppData\Local\Temp\pip-install-0e9wj35t\pycrypto\
You are using pip version 10.0.1, however version 18.0 is available.
You should consider upgrading via the 'python -m pip install --upgrade pip' command.

----END----

从上面的错误日志来看，需要用到一个cl.exe命令，这个命令的路径存在于Microsoft Visual Studio 14.0或Windows Kits中，但是，孤的电脑上是没有的。

解决的方法当然是安装Microsoft Visual Studio，参考链接的解决方法也是说要安装一个，不过更详细一些。

另外，错误日志还提示GMP or MPIR library缺失，是否安装好Microsoft Visual Studio就有了呢？然后，之后就可以安装pycrypto了。

接下来，分为两步解决这个问题：

1.安装Microsoft Visual Studio；

2.安装pycrypto（此步骤的日志可以检查GMP or MPIR library是否已经有了，若是没有，且pycrypto安装失败，那么再找办法）；

0825-0900新发现：

孤的电脑已经有错误日志中提到的Microsoft Visual Studio 14.0或Windows Kits目录及相关文件了，可是看来，上面说的解决方法是不对的，还需要继续dig才是

操作系统模块安装了Visual Studio 2015的部分功能吗？下图的这些是怎么来的呢？

既然如此，那么，又要怎么解决呢？再看看参考链接吧！

去Visual Studio官网看了一遍，好多软件，不愧是Microsoft！对于一位非Windows系程序员，要选对软件有些困难啊！

还要找找，到底Windows 10上能否安装pycrypto！

哎呀，都要耗费精时啊！

检查Python标准库，居然没有找到加密、安全相关的模块，搜索security、crypto都没有找到想要的——使用各种加密算法，看来，必须要用第三方库了，比如pycrypto。

参考链接：

windows 下的python 安装pycrypto by 园友 anne的夏天

python 加密解密 by 园友 jihite

0825-0930更新：哇哦，Ubuntu（18.04）上安装pycrypto好方便啊！嗖的一下就安装好勒！

安装好了，可是，import pycrypto失败！

>>> import pycrypto
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ModuleNotFoundError: No module named 'pycrypto'

疑问：怎么找到一个模块的用法呢？官网吗？通过模块本身可以知道吗？

参考下面的链接（官文）可以初步知道pycrypto模块的用法：

Python Cryptography Toolkit