pip install报错 HTTPSConnectionPool(host='files.pythonhosted.org', port=443)连接超时

问题描述：

在pip install安装代码库的时候，提示超时，报错信息如下。

Could not install packages due to an EnvironmentError: HTTPSConnectionPool(host='files.pythonhosted.org', port=443): Max retries exceeded with url: /packages/24/bd/adb580d907a71d1082b3eaa47790f199f6e73eb198353adac48b035d00ff/characters-0.1.0.tar.gz (Caused by ConnectTimeoutError(<pip._vendor.urllib3.connection.VerifiedHTTPSConnection object at 0x104cae828>, 'Connection to files.pythonhosted.org timed out. (connect timeout=15)'))
 

解决办法：

在install 命令行后面指定下载源，如 pip install bs4 -i https://pypi.doubanio.com/simple

引用：

https://www.cnblogs.com/valin/p/12315195.html