python3安装Crypto过程

      公司app登录接口在传参时，有个加密字段“——key”。在使用python做接口测试时，调研可以通过Crypto包进行加密处理，而Crypto包是第三方包，需要进行安装。

      1.使用python3 -m pip install Crypto进行安装；

结果，安装失败，报错如下：

Could not fetch URL https://pypi.org/simple/crypto/: There was a problem confirming the ssl certificate: HTTPSConnectionPool(host='pypi.org', port=443): Max retries exceeded with url: /simple/crypto/ (Caused by SSLError(SSLCertVerificationError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: self signed certificate in certificate chain (_ssl.c:1122)'))) - skipping
ERROR: Could not find a version that satisfies the requirement Crypto (from versions: none)
ERROR: No matching distribution found for Crypto
Could not fetch URL https://pypi.org/simple/pip/: There was a problem confirming the ssl certificate: HTTPSConnectionPool(host='pypi.org', port=443): Max retries exceeded with url: /simple/pip/ (Caused by SSLError(SSLCertVerificationError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: self signed certificate in certificate chain (_ssl.c:1122)'))) - skipping

在网上搜索解决方法后，修改了安装命令。

       2.使用命令python3 -m pip  --trusted-host pypi.org install Crypto进行安装；

结果，仍然安装失败，报错如下：

ERROR: Could not install packages due to an EnvironmentError: HTTPSConnectionPool(host='files.pythonhosted.org', port=443): Max retries exceeded with url: /packages/fc/bb/0b812dc02e6357606228edfbf5808f5ca0a675a84273578c3a199e841cd8/crypto-1.4.1-py2.py3-none-any.whl (Caused by SSLError(SSLCertVerificationError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: self signed certificate in certificate chain (_ssl.c:1122)')))

继续寻找解决方法，修改了安装源，指定为豆瓣的镜像源。

      3.python3 -m pip install Crypto -i http://pypi.douban.com/simple --trusted-host pypi.douban.com

结果，安装成功。如下：

Installing collected packages: shellescape, pyyaml, Naked, Crypto
Successfully installed Crypto-1.4.1 Naked-0.1.31 pyyaml-5.4.1 shellescape-3.8.1

      到了这一步，Crypto算是安装成功了，但是在使用from Crypto.PublicKey import RSA导入时，提示并没有Crypto库。果然不会这么顺利的，又在网上查找解决方法。

在进到python3安装路径后，进到site-packages目录，查看包名是小写的（crypto，crypto-1.4.1.dist-info），于是将首字母修改为大写。

      当再次导入包时from Crypto.PublicKey import RSA，又提示没有PublicKey，没辙，又在网上搜索解决办法，找到个答案说需要安装pycryptodome。还能怎么办，继续安装呗！

      4.python3 -m pip install pycryptodome -i http://pypi.douban.com/simple --trusted-host pypi.douban.com

至此，终于完成安装了。

      记此，避免后续继续踩坑。