在Windows上安装yaml模块，使用pip安装。
>pip install PyYAML
Collecting PyYAML
Downloading https://files.pythonhosted.org/packages/da/7e/b82dad5d7343eb3d53cf84aaefb53515a659c55b1cb7c328287256c1c156/PyYAML-5.1.2-cp27-cp27m-win_amd64.whl (210kB)
100% |████████████████████████████████| 215kB 605kB/s
Installing collected packages: PyYAML
Successfully installed PyYAML-5.1.2
You are using pip version 18.1, however version 19.2.3 is available.
You should consider upgrading via the 'python -m pip install --upgrade pip' command.
测试OK。
>python
Python 2.7.16 (v2.7.16:413a49145e, Mar 4 2019, 01:37:19) [MSC v.1500 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import yaml
>>>