ntpupdate.py

import socket
import struct
import time

# datetime.date(1970, 1, 1) - datetime.date(1900, 1, 1)
NTP_DELTA = 2208988800
NTP_SERVER = '0.cn.pool.ntp.org'

def get_ntp_time():
    data = bytearray(48)
    data[0] = 0x1B
    val = 0

    addr = socket.getaddrinfo(NTP_SERVER, 123)[0][-1]
    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    n = sock.sendto(data, addr)
    data, addr = sock.recvfrom(2048)
    val = struct.unpack("!12I", data)[10]

    return val - NTP_DELTA