class DB:
    connection_pool = None

    @classmethod
    def get_cursor(cls):
        connection = cls.connection_pool.getconn()
        return connection, connection.cursor()

    @classmethod
    def close_cursor(cls, connection, cursor):
        cursor.close()
        cls.connection_pool.putconn(connection)

    @classmethod
    def fetchone(cls, query, *args):
        connection, cursor = cls.get_cursor()
        cursor.execute(query, args)
        res = cursor.fetchone(), cursor.query
        cls.close_cursor(connection, cursor)

        return res

    @classmethod
    def fetchall(cls, query, *args):
        connection, cursor = cls.get_cursor()
        cursor.execute(query, args)
        res = cursor.fetchall(), cursor.query
        cls.close_cursor(connection, cursor)

        return res