Greetings!
If someone has use for it:
I have created a Python3 client for the OPNsense API: github.com/O-X-L/opnsense-api-client (https://github.com/O-X-L/opnsense-api-client), pypi.org/project/oxl-opnsense-client (https://pypi.org/project/oxl-opnsense-client/)
Docs: python-opnsense.oxl.app (https://python-opnsense.oxl.app)
It is based on our Ansible Collection for OPNsense (https://github.com/O-X-L/ansible-opnsense) that is already used by many admins.