1

尝试在 python 中比较日期时，我注意到一些非常奇怪的行为。我正在尝试使用日期来检查是否将项目添加到 MySQL 数据库（使用 mysqldb 库），并且在比较日期时，我得到了奇怪的行为：

代码是：

   latestDate = pullDateFromTable() #pull the latest item from the table
   for transaction in transactions:
        print "Transaction Time:",transaction.date
        print "Latest Entry:",latestDate
        if transaction.date > latestDate:
            print "Transaction is new, added product"
            #insert item to MySQL database
        else:
            print "Old transaction, did not add product"

输出是：

Transaction Time: Thu Oct  4 11:42:25 2012
Latest Entry: Thu Oct  4 11:42:25 2012
Old transaction, did not add product

Transaction Time: Wed Oct  3 22:11:48 2012
Latest Entry: Thu Oct  4 11:42:25 2012
Transaction is new, added product

Transaction Time: Wed Oct  3 19:32:56 2012
Latest Entry: Thu Oct  4 11:42:25 2012
Transaction is new, added product

Transaction Time: Wed Oct  3 17:46:35 2012
Latest Entry: Thu Oct  4 11:42:25 2012
Transaction is new, added product

Transaction Time: Wed Oct  3 17:46:35 2012
Latest Entry: Thu Oct  4 11:42:25 2012
Transaction is new, added product

Transaction Time: Wed Oct  3 17:46:35 2012
Latest Entry: Thu Oct  4 11:42:25 2012
Transaction is new, added product

Transaction Time: Wed Oct  3 16:25:06 2012
Latest Entry: Thu Oct  4 11:42:25 2012
Transaction is new, added product

Transaction Time: Wed Oct  3 14:00:48 2012
Latest Entry: Thu Oct  4 11:42:25 2012
Transaction is new, added product

Transaction Time: Wed Oct  3 11:46:20 2012
Latest Entry: Thu Oct  4 11:42:25 2012
Transaction is new, added product

Transaction Time: Wed Oct  3 11:46:20 2012
Latest Entry: Thu Oct  4 11:42:25 2012
Transaction is new, added product

Transaction Time: Wed Oct  3 11:22:37 2012
Latest Entry: Thu Oct  4 11:42:25 2012
Transaction is new, added product

Transaction Time: Wed Oct  3 09:05:13 2012
Latest Entry: Thu Oct  4 11:42:25 2012
Transaction is new, added product

Transaction Time: Wed Oct  3 09:05:13 2012
Latest Entry: Thu Oct  4 11:42:25 2012
Transaction is new, added product

Transaction Time: Wed Oct  3 09:05:13 2012
Latest Entry: Thu Oct  4 11:42:25 2012
Transaction is new, added product

Transaction Time: Tue Oct  2 07:38:25 2012
Latest Entry: Thu Oct  4 11:42:25 2012
Transaction is new, added product

Transaction Time: Mon Oct  1 17:39:52 2012
Latest Entry: Thu Oct  4 11:42:25 2012
Old transaction, did not add product

Transaction Time: Mon Oct  1 15:05:29 2012
Latest Entry: Thu Oct  4 11:42:25 2012
Old transaction, did not add product

Transaction Time: Sun Sep 30 20:56:38 2012
Latest Entry: Thu Oct  4 11:42:25 2012
Old transaction, did not add product

Transaction Time: Sun Sep 30 09:52:09 2012
Latest Entry: Thu Oct  4 11:42:25 2012
Old transaction, did not add product

您会注意到星期二或星期三（10 月 2 日和 3 日）的日期大于最新日期（10 月 4 日），但 9 月或 10 月 1 日的日期小于。

关于为什么会这样的任何想法？

4

1 回答 1

6

您的日期似乎是字符串，并且它们按字母顺序进行比较。W紧随其后T。

于 2012-10-04T18:56:24.857 回答