def drop(self, site, rule=None):
        if rule is None:
            rule = '%'
        with self.connection() as db:
            cursor = db.execute('SELECT id FROM contexts '
                                'WHERE site = ? '
                                'AND rule LIKE ?;', (site, rule))
            if cursor.fetchone() not in None:
                db.execute('DELETE FROM contexts '
                           'WHERE site = ? AND rule LIKE ?;', (site, rule))

                db.commit()
dataset/ETHPy150Open willowtreeapps/tango-core/tango/shelf.py/SqliteConnector.drop/operator `is not` -> `not in`