WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after con..._综合

python安装插件提示如下错误，解决方案：

(py37_vnpy) D:\proj\vnpy>pip install requirements.txt
Looking in indexes: https://pypi.tuna.tsinghua.edu.cn/simple
WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ProxyError('Cannot connect to proxy.', OSError(0, 'Error')
)': /simple/requirements-txt/
WARNING: Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ProxyError('Cannot connect to proxy.', OSError(0, 'Error')
)': /simple/requirements-txt/
WARNING: Retrying (Retry(total=2, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ProxyError('Cannot connect to proxy.', OSError(0, 'Error')
)': /simple/requirements-txt/
ERROR: Operation cancelled by user

WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after con...

错误截图

打开 windows 目录: C:\Users\[用户名]\显示隐藏文件

显示隐藏文件

进入以下目录：
C:\Users\[用户名]\AppData\Roaming\pip

进入配置文件pip.ini目录

修改 pip.ini 文件
[global]
index-url = http://pypi.douban.com/simple
trusted-host =  pypi.douban.com

添加trusted-host配置