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

安装boost时候报错

Looking in indexes: https://pypi.douban.com/simple
WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ProxyError('Cannot connect to proxy.', RemoteDisconnected('Remote end closed connection without response'))': /simple/boost/
WARNING: Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ProxyError('Cannot connect to proxy.', RemoteDisconnected('Remote end closed connection without response'))': /simple/boost/
WARNING: Retrying (Retry(total=2, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ProxyError('Cannot connect to proxy.', RemoteDisconnected('Remote end closed connection without response'))': /simple/boost/
WARNING: Retrying (Retry(total=1, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ProxyError('Cannot connect to proxy.', RemoteDisconnected('Remote end closed connection without response'))': /simple/boost/
WARNING: Retrying (Retry(total=0, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ProxyError('Cannot connect to proxy.', RemoteDisconnected('Remote end closed connection without response'))': /simple/boost/
ERROR: Could not find a version that satisfies the requirement boost (from versions: none)
ERROR: No matching distribution found for boost

原因
pip源连接证书验证失败
解决
将pip源调整为国内的源

pip install boost -i http://mirrors.aliyun.com/pypi/simple --trusted-host mirrors.aliyun.com