Comment 6 for bug 1967793

<SOLVED> formatter.py missing in Python3.10. Simply copy the formatter.py file from any other version into the Python3.10 folder.

I had the same problem with Pysolfc and Python3.10, but I have found the answer to the problem. In version of Python 3.10 they left out formatter.py. I am using a fork of Ubuntu (Linux Mint) so a few things may vary in location of the file. I installed Python3.8, so in /usr/lib/python3.8/ there was the file formatter.py. I copied the formatter.py into the usr/lib/python3.10/ where it was missing. Then tried to open Pysolfc and all is well. I hope this helps everyone else as much as it did me. I read that the creators of Python said that the file formatter.py wasn't used anymore and was outdated. I beg to differ as would the rest you.
Before this I tried changing the default python version from 3.10 to 3.8 with sudo update-alternatives --config python and choose version 3.8, but that didn't help. So, I changed the python version back to Python3.10.4
Have a great day!
Thanks Joey