已加载“C:\Windows\SysWOW64\ntdll.dll” 无法查找或打开 PDB 文件。
manual upgrade
下载pip的源码https://pypi.org/project/pip/#files
替换lLib->site-packages->pip,pip-*-py*.egg-info
auto upgrade
linux/mac:pip install --upgrade pip
windows: python -m pip install --upgrade pip