Python-сообщество

import socket
import firebirdsql
from datetime import datetime, timedelta
from json import dumps
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = 'localhost'
port = 2020
s.connect((host, port))
conn = firebirdsql.connect(***)
curs = conn.cursor()
nowtime = datetime.now()
delttime = nowtime - timedelta(seconds=30)
def json_serial(obj):
    if isinstance(obj, datetime):
        serial = obj.strftime('%d.%m.%Y %H:%M:%S')
        return serial
query = 'select PROJ_ID_, OBJ_ID_, TIME_, LON_, LAT_, SPEED_ from basedata where TIME_ between ? and ?'
params = [delttime.strftime('%d.%m.%Y %H:%M:%S'), nowtime.strftime('%d.%m.%Y %H:%M:%S')]
curs.execute(query, params)
for c in curs.fetchall():
    response = dumps(c, default=json_serial)
    s.send(response.encode())
s.close()