遇到問題：
最近PIP安裝軟件總是報錯，報錯提示如下：
1.WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ConnectTimeoutError(<pip._vendor.urllib3.connection.VerifiedHTTPSConnection object at 0x000001E6D75D4220>, 'Connection to files.pythonhosted.org timed out.
2.ERROR: Could not install packages due to an EnvironmentError: HTTPSConnectionPool(host='files.pythonhosted.org', port=443): Max retries exceeded with url: /packages/91/d2/30ecd905746d1fee4004daae3f0051bf4b305bee1fe578bd7d1ea712d571/Pillow-7.2.0-cp38-cp38-win_amd64.whl (Caused by ConnectTimeoutError(<pip._vendor.urllib3.connection.VerifiedHTTPSConnection object at 0x000001E6D75D4970>, 'Connection to files.pythonhosted.org timed out. (connect timeout=15)'))
如圖：
解決辦法:
以管理員身份運行cmd，cd至python Scripts目錄，我的安裝在"D:\Program Files\Python38\Scripts",將pip install xxx命令調整如下即可：
pip install xxx -i http://pypi.douban.com/simple --trusted-host pypi.douban.com，xxx為要安裝的軟件，如：
安裝pillow軟件：pip install pillow -i http://pypi.douban.com/simple --trusted-host pypi.douban.com
安裝robotframework-ride軟件：pip install robotframework-ride -i http://pypi.douban.com/simple --trusted-host pypi.douban.com
