git_utils.py

import os

def find_repo_root(start_dir='.'):
    start_dir = os.path.abspath(start_dir)
    if '.git' not in os.listdir(start_dir):
        assert start_dir != '/', "No Git repo found in given folder or its parents."
        return find_repo_root(os.path.join(start_dir, '..'))
    return start_dir

def get_branch_name(start_dir='.'):
    root = find_repo_root(start_dir)
    with open(os.path.join(root, '.git/HEAD'), 'r') as f:
        branch = f.readline().replace('ref: refs/heads/', '').split('\n', 1)[0]
    return branch