一、用命令安装yaml
pip install pyyaml

pip不是内部命令解决办法：将python下的Scripts文件路径配置到path变量里如：D:\python\Scripts

Fatal error in launcher: Unable to create process using '"c:\program files\python37\python.exe" "D:\Python37\Python37\Scripts\pip.exe" install pyyaml'

解决办法：python -m pip install pyyaml
验证yaml安装是否成功:python 回车、输入import不报错即可

二、使用whl文件安装
1、pip install wheel
2、pip install xxx.whl
我安装过程
1.python -m pip install wheel #安装过程提示Requirement 'PyYAML-3.13-cp37-cp37m-win_amd64.whl' looks like a filename, but the file does not exist解决办法将文件安装到绝对路径下
2.python -m pip install PyYAML-3.13-cp37-cp37m-win_amd64.whl