From minima03 above... I did what mini described, and I also used usr/bin/python3 for everything and it is working FYI. I am using Xcode 12.4 on Big Sur. I use pyenv and have 3 pythons installed, system, 2.7.18 and 3.9.1.
I do get this error at the top of the output, but then it runs the python code fine after that anyway:
2021-02-12 12:28:15.725010-0500 python3[42530:1404893] Failed to open macho file at /Applications/Xcode.app/Contents/Developer/usr/bin/python3 for reading: Too many levels of symbolic links