conn = psycopg2.connect(host="localhost", dbname='postgres', user='postgres', password=postgres)
cur = conn.cursor()
cur.execute("select id_log, nm_ip, dh_chamada, nm_tipo, nm_contexto, cd_http, in_tamanho from tb_log")
cur.fetchone()

cur.execute("select id_log, nm_ip, dh_chamada, nm_tipo, nm_contexto, cd_http, in_tamanho from tb_log")
psycopg2.ProgrammingError: relation "tb_log" does not exist
LINE 1: ...amada, nm_tipo, nm_contexto, cd_http, in_tamanho from tb_log
                                                                 ^

SELECT id_log, nm_ip, dh_chamada, nm_tipo, nm_contexto, cd_http, in_tamanho
    FROM tb_log;

1,'12             ','2018-06-07 13:03:13','HEAD ','/FDSFDS',200,1000