def option_list_all(self):
        """Get a list of all options, including those in option groups."""
        res = self.option_list[:]
        for i in self.option_groups:
            res.extend(i.option_list)

        return res
Get a list of all options, including those in option groups.
stackoverflow/venv/lib/python3.6/site-packages/pip-19.0.3-py3.6.egg/pip/_internal/cli/parser.py