conexion = psycopg2.connect("host=localhost port=5432 dbname='TECNIKA_PRUEBAS_2' user='master' password='1234'")
                cr = conexion.cursor()
                cr.execute('select id, internal_number from account_invoice limit 5')
                registros = cr.fetchall()
                for reg in registros:
                    print ("Registros del query", reg)