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

安裝boost時候報錯

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源連接證書驗證失敗
解決
將pip源調整爲國內的源

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