def work self last_time Send notifications about new questions to all

    def work(self, last_time):
        """
        Send notifications about new questions to all users.

        @param last_time: last time when script was worked.
        """

        # Select all users, whose last notification time is too old.
        if self.debug_last_time:
            last_time = datetime.now()#self.debug_last_time
        else:
            last_time = datetime.now() - timedelta(seconds=self.period_length)
        self.cursor.execute("""
                            SELECT u.id, u.email, u.login, u.homecity,
                                   u.qnotified
                            FROM users u
                            LEFT JOIN cities_in_users ciu ON ciu.user = u.id
                            WHERE u.question_notify = %s
                                AND (qnotified IS NULL OR qnotified < %s)""",
                            (self.period_type, last_time))
# и потом ...

        # 1) Select questions that needs answers
        self.cursor.execute("""
                            SELECT q.id, q.title, q.city, q.user
                            FROM articles q
                            WHERE q.atype = 1 AND q.date > %s AND q.countAnswers < %s
                            ORDER BY q.date ASC""",
                            (last_time, settings.QUESTION_NEEDS_ANSWERS))