记录一下
pip安装flask，显示WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by ‘SSLError(“Can’t connect to HTTPS URL because the SSL module is not available.”)’: /simple/flask/
解决方案：换源
pip install flask -i http://mirrors.aliyun.com/pypi/simple --trusted-host mirrors.aliyun.com