pip 安装第三方包超时

错误：

2021-02-22 13:24:45WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'ReadTimeoutError("HTTPSConnectionPool(host='pypi.org', port=443): Read timed out. (read timeout=15)")': /simple/pymysql/

解决办法：添加超时时间

pip --default-timeout=100 install pymysql