pip install gnusocial
or
python3 setup.py install
You can also install python-gnusocial package from AUR.
Documentation is hosted at https://pythonhosted.org/gnusocial/
>>> from gnusocial import statuses
>>> r = statuses.update('https://gnusocial.server.com', "I've just installed #pygnusocial!", source='python3', username='username', password='password',)
If you want to help with the development of pygnusocial, check out the contribution guide.