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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_commit_if_possible(filename):
 """Try to retrieve VCS information for a given file. Currently only supports git using the gitpython package. Parameters filename : str Returns ------- path: str The base path of the repository commit: str The commit hash is_dirty: bool True if there are uncommitted changes in the repository """

    # git
    if opt.has_gitpython:
        from git import Repo, InvalidGitRepositoryError
        try:
            directory = os.path.dirname(filename)
            repo = Repo(directory, search_parent_directories=True)
            try:
                path = repo.remote().url
            except ValueError:
                path = 'git:/' + repo.working_dir
            is_dirty = repo.is_dirty()
            commit = repo.head.commit.hexsha
            return path, commit, is_dirty
        except (InvalidGitRepositoryError, ValueError):
            pass
    return None, None, None