一、
1.列出已pip安装的包
C:\Users\xxx\AppData\Local\Programs\Python\Python37\Scripts>pip list Package Version --------------- ------- numpy 1.17.3 pandas 0.25.3 pip 18.1 python-dateutil 2.8.1 pytz 2019.3 setuptools 40.6.2 six 1.13.0
2.将已安装的包输出到文本
C:\Users\xxx\AppData\Local\Programs\Python\Python37\Scripts>pip freeze >1.txt
3.升级python后，安装1.txt中保存的包
pip install -r 1.txt
原文：https://www.cnblogs.com/joeshang/p/11833935.html