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 test_reverse_iso8601_datetime():
    dates = [
        ("2011-01-01T00:00:00+00:00", datetime(2011, 1, 1, tzinfo=pytz.utc)),
        ("2011-01-01T23:59:59+00:00", datetime(2011, 1, 1, 23, 59, 59, tzinfo=pytz.utc)),
        ("2011-01-01T23:59:59.001000+00:00", datetime(2011, 1, 1, 23, 59, 59, 1000, tzinfo=pytz.utc)),
        ("2011-01-01T23:59:59+02:00", datetime(2011, 1, 1, 21, 59, 59, tzinfo=pytz.utc))
    ]

    for date_string, expected in dates:
        yield assert_equal, inputs.datetime_from_iso8601(date_string), expected