from pathlib import Path
from git import Repo

def repo() -> 'Repo':
    from git import Repo  # type: ignore
    return Repo(Path(__file__).parent, search_parent_directories=True)

repository = repo()
repository.active_branch.name    

❯ python3 test.py
Traceback (most recent call last):
  File "/test.py", line 9, in <module>
    repository.active_branch.name
  File "/venv/lib/python3.10/site-packages/git/repo/base.py", line 797, in active_branch
    return self.head.reference
  File "/venv/lib/python3.10/site-packages/git/refs/symbolic.py", line 294, in _get_reference
    raise TypeError("%s is a detached symbolic reference as it points to %r" % (self, sha))
TypeError: HEAD is a detached symbolic reference as it points to '7sfaslkhfuhajkfnjaksdhfc4ede32c'