我有一个关于游标如何在python中执行查询的问题。这是有问题的代码块：
state county prime_mover long lat
1: AZ Maricopa GT -111.88668 33.58126
2: AZ Maricopa GT -111.88668 33.58126
3: CA Los Angeles CT -118.29410 34.06683
4: CA Orange CT -117.73632 33.69611
5: CA Los Angeles CT -118.29410 34.06683
6: CT Fairfield CT -73.35118 41.29633
7: FL Hillsborough GT -82.47527 27.87826
8: IN Morgan CT -86.49791 39.52721
9: MA Barnstable GT -70.21598 41.79520
10: MA Nantucket GT -70.05841 41.29880
11: MA Essex GT -70.98384 42.64042
12: MN Dakota GT -93.04962 44.70344
13: NJ Cape May CT -74.80790 39.15476
14: NJ Salem GT -75.36532 39.58720
15: NJ Middlesex CT -74.42345 40.45429
16: NY Kings GT -73.95052 40.64792
17: NC Buncombe CT -82.50883 35.62002
18: SC Anderson CT -82.61956 34.57094
19: TN Shelby CT -89.99297 35.22379
20: TX Tarrant CT -97.29396 32.79856
因此，我要附加的所有列表都包含实时数据，这些数据会在第二秒发生变化。我已经注意到，当我在代码末尾打印read_time时，每次的列表都是完全相同的。我的问题是，执行查询后，数据是否始终相同？我希望看到这样的阅读时间：
for sleeper in range (2):
cur.execute("QUERY")
for row in cur:
Demand.append(str(row[2]))
ComponentID.append(str(row[3]))
DeviceID.append(str(row[1]))
read_time.append(str(row[4]))
print read_time
del read_time[:]
相反，我看到的是：
2018-08-20 15:39:08
2018-08-20 15:59:25