I just did a fresh install of Mint 20 which comes with LO 6.4xx. I did Tools-->Macros-->Organize Macros in Cakc but there is no entry for Python.
A few years ago when I did the same thing with Mint 18 I had the same problem. I thought what I did to fix it was, create a Scripts/python folder in .config/libreoffice/4/user/Scripts/python and be sure that uno.py and unohelper.py were in the site-packages folder of my virtual environment. Also in an effort to get this working I set the security level for macros to low.
What else do I need to do to get python macros working?
Thanks, Jim