_pygit2.GitError: Repository not found at

Question

    def save_experiment_config(self):
        with open(os.path.join(self.experiment_dir, 'parameters.txt'), 'w') as file:
            config_dict = vars(self.args)
            for k in vars(self.args):
                file.write(f"{k}={config_dict[k]} \n")
            repo = Repository('.')
            file.write(f"git-repo={repo.head.shorthand} \n")

I ran the code, but occur "_pygit2.GitError: Repository not found at .".

I don't know how can I deal with it? Thank you for your help!