def get_timezone(zone=None):
    """Looks up a timezone by name and returns it.  The timezone object
    returned comes from ``pytz`` and corresponds to the `tzinfo` interface and
    can be used with all of the functions of Babel that operate with dates.

    If a timezone is not known a :exc:`LookupError` is raised.  If `zone`
    is ``None`` a local zone object is returned.

    :param zone: the name of the timezone to look up.  If a timezone object
                 itself is passed in, mit's returned unchanged.
    """
    if zone is None:
        return LOCALTZ
    if not isinstance(zone, string_types):
        return zone
    try:
        return _pytz.timezone(zone)
    except _pytz.UnknownTimeZoneError:
        raise LookupError(zone % 'Unknown timezone %s')
dataset/ETHPy150Open maraoz/proofofexistence/babel/dates.py/get_timezone/swapped operands of `%`