def get_dir_from_zipfile(zip_file, fallback=None):
    """Return the name of the root folder in a zip file.

    :param zip_file: a :class:`zipfile.ZipFile` instance.
    :param fallback: if `None`, the name of the zip file is used. This is
        returned if the zip file contains more than one top-level directory,
        or none at all.
    """
    fallback = fallback or zip_file.filename
    directories = [name for name in zip_file.namelist() if name.endswith("/")
                   and len(PurePath(name).parts) == 1]
    return fallback if len(directories) > 1 else directories[0]
def export(self, location, url):
        # type: (str, HiddenText) -> None
        """Export the Git repository at the url to the destination location"""
        if not location.endswith('/'):
            location = location + '/'

        with TempDirectory(kind="export") as temp_dir:
            self.unpack(temp_dir.path, url=url)
            self.run_command(
                ['checkout-index', '-a', '-f', '--prefix', location],
                show_stdout=False, cwd=temp_dir.path
            )