出现错误，请帮助。

Python 3.7.0 (v3.7.0:1bf9cc5093, Jun 27 2018, 04:06:47) [MSC v.1914 32 bit (Intel)] on win32
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>>>
RESTART: C:\Users\Administrator.SC-201905201543\Desktop\vestor\vestor\sis数据获取-py37.py
Traceback (most recent call last):
  File "C:\Users\Administrator.SC-201905201543\Desktop\vestor\vestor\sis数据获取-py37.py", line 15, in <module>
    class TagData(Structure):
NameError: name 'Structure' is not defined
>>>

代码如下 ：
# -*- coding: utf-8 -*-

import os
import time
#from ctypes import *
import pymysql

import datetime

DLL_PATH = os.path.dirname(__file__) + '\\'
DLL_FILE = os.path.join(DLL_PATH, 'RTDBInterface.dll')
INI_FILE = os.path.join(DLL_PATH, 'VeStore.ini')


class TagData(Structure):
    _fields_ = [('value', c_double), ('time', c_long), ('status', c_int)]


class ReadHiDataRequest(Structure):
    _fields_ = [('stTime', c_long), ('enTime', c_long), ('tPeriod', c_long), ('reqType', c_int),
                ('pointName', c_char_p)]

你好，你这里是缺少了 Structure 这个超类。
若有定义的，则请补全。若没有定义的，则在：
import datetime
这句下面定义这个超类(定义如下)，临时处理看是否可行。
class Structure:pass