def time_delta(self):
    h = (self._end_time.hour - self._start_time.hour)
    m = (self._end_time.minute - self._start_time.minute)
    s = (((m * 60) + self._end_time.second) - self._start_time.second)
    return datetime.timedelta(hours=h, seconds=s)
def time_delta(self):
    h = (self._end_time.hour - self._start_time.hour)
    m = (self._end_time.minute - self._start_time.minute)
    s = (((m * 60) + self._end_time.second) - self._start_time.second)
    return datetime.timedelta(hours=h, seconds=s)