对Python日期字符串列表进行排序

Question

我有一个列表：

a = ['7-Mar-14', '10-Mar-14', '11-Mar-14', '14-Mar-14', '15-Mar-14', '17-Mar-14', '22-Mar-14', '23-Mar-14', '25-Mar-14', '1-Nov-13', '5-Nov-13', '8-Nov-13', '23-Nov-13', '24-Nov-13', '25-Nov-13', '26-Nov-13', '3-Dec-13', '9-Dec-13', '13-Dec-13', '9-Jan-14', '17-Jan-14', '20-Jan-14', '8-Feb-14', '9-Feb-14', '10-Feb-14', '11-Feb-14', '12-Feb-14', '16-Feb-14', '17-Feb-14', '19-Feb-14', '22-Feb-14', '26-Feb-14', '28-Feb-14', '2-Mar-14', '4-Mar-14', '31-Mar-14', '1-Apr-14', '2-Apr-14', '4-Apr-14', '6-Apr-14', '8-Apr-14', '9-Apr-14', '15-Apr-14', '16-Apr-14', '17-Apr-14', '18-Apr-14', '20-Nov-13', '5-Dec-13', '15-Dec-13', '15-Jan-14', '19-Jan-14', '26-Jan-14', '3-Feb-14', '6-Feb-14', '14-Feb-14', '21-Feb-14', '24-Feb-14', '1-Mar-14', '5-Mar-14', '12-Mar-14', '19-Mar-14', '20-Mar-14', '21-Mar-14', '24-Mar-14', '26-Mar-14', '27-Mar-14', '29-Mar-14', '30-Mar-14', '7-Apr-14', '10-Apr-14', '11-Apr-14', '12-Apr-14', '27-Nov-13', '16-Jan-14', '27-Jan-14', '6-Mar-14', '13-Mar-14', '16-Mar-14', '18-Mar-14', '28-Mar-14', '3-Apr-14', '5-Apr-14']

有没有办法可以按照实际的日期和时间来排序这个列表呢？

Answer 1

我的列表里包含了格式为 "%Y-%m-%d %H:%M:%S" 的 'datetime' 字符串，具体如下：

from datetime import datetime

dateList = ['2018-09-07 19:00:46',
            '2018-09-03 19:39:42',
            '2018-09-04 09:46:42',
            '2018-09-02 14:21:22',
            '2018-09-05 19:19:34',
            '2018-09-03 13:35:17',
            '2018-09-05 08:19:35',
            '2018-09-07 05:22:54',
            '2018-09-07 19:01:02']

我把这些字符串转换成了正确格式的日期时间对象，然后使用 sorted(）函数对它们进行了排序，这个函数是在一个列表推导式中使用的：

sorted([datetime.strptime(dt, "%Y-%m-%d %H:%M:%S") for dt in dateList])

最终得到了一个排序好的日期时间对象列表，具体如下：

[datetime.datetime(2018, 9, 2, 14, 21, 22),
 datetime.datetime(2018, 9, 3, 13, 35, 17),
 datetime.datetime(2018, 9, 3, 19, 39, 42),
 datetime.datetime(2018, 9, 4, 9, 46, 42),
 datetime.datetime(2018, 9, 5, 8, 19, 35),
 datetime.datetime(2018, 9, 5, 19, 19, 34),
 datetime.datetime(2018, 9, 7, 5, 22, 54),
 datetime.datetime(2018, 9, 7, 19, 0, 46),
 datetime.datetime(2018, 9, 7, 19, 1, 2)]

Answer 2

你可以使用 list.sort 和 datetime.datetime.strptime：

>>> from datetime import datetime
>>> a = ['7-Mar-14', '10-Mar-14', '11-Mar-14', '14-Mar-14', '15-Mar-14', '17-Mar-14', '22-Mar-14', '23-Mar-14', '25-Mar-14', '1-Nov-13', '5-Nov-13', '8-Nov-13', '23-Nov-13', '24-Nov-13', '25-Nov-13', '26-Nov-13', '3-Dec-13', '9-Dec-13', '13-Dec-13', '9-Jan-14', '17-Jan-14', '20-Jan-14', '8-Feb-14', '9-Feb-14', '10-Feb-14', '11-Feb-14', '12-Feb-14', '16-Feb-14', '17-Feb-14', '19-Feb-14', '22-Feb-14', '26-Feb-14', '28-Feb-14', '2-Mar-14', '4-Mar-14', '31-Mar-14', '1-Apr-14', '2-Apr-14', '4-Apr-14', '6-Apr-14', '8-Apr-14', '9-Apr-14', '15-Apr-14', '16-Apr-14', '17-Apr-14', '18-Apr-14', '20-Nov-13', '5-Dec-13', '15-Dec-13', '15-Jan-14', '19-Jan-14', '26-Jan-14', '3-Feb-14', '6-Feb-14', '14-Feb-14', '21-Feb-14', '24-Feb-14', '1-Mar-14', '5-Mar-14', '12-Mar-14', '19-Mar-14', '20-Mar-14', '21-Mar-14', '24-Mar-14', '26-Mar-14', '27-Mar-14', '29-Mar-14', '30-Mar-14', '7-Apr-14', '10-Apr-14', '11-Apr-14', '12-Apr-14', '27-Nov-13', '16-Jan-14', '27-Jan-14', '6-Mar-14', '13-Mar-14', '16-Mar-14', '18-Mar-14', '28-Mar-14', '3-Apr-14', '5-Apr-14']
>>> a.sort(key=lambda date: datetime.strptime(date, "%d-%b-%y"))
>>> a
['1-Nov-13', '5-Nov-13', '8-Nov-13', '20-Nov-13', '23-Nov-13', '24-Nov-13', '25-Nov-13', '26-Nov-13', '27-Nov-13', '3-Dec-13', '5-Dec-13', '9-Dec-13', '13-Dec-13', '15-Dec-13', '9-Jan-14', '15-Jan-14', '16-Jan-14', '17-Jan-14', '19-Jan-14', '20-Jan-14', '26-Jan-14', '27-Jan-14', '3-Feb-14', '6-Feb-14', '8-Feb-14', '9-Feb-14', '10-Feb-14', '11-Feb-14', '12-Feb-14', '14-Feb-14',
'16-Feb-14', '17-Feb-14', '19-Feb-14', '21-Feb-14', '22-Feb-14', '24-Feb-14', '26-Feb-14', '28-Feb-14', '1-Mar-14', '2-Mar-14', '4-Mar-14', '5-Mar-14', '6-Mar-14', '7-Mar-14', '10-Mar-14', '11-Mar-14', '12-Mar-14', '13-Mar-14', '14-Mar-14', '15-Mar-14', '16-Mar-14', '17-Mar-14', '18-Mar-14', '19-Mar-14', '20-Mar-14', '21-Mar-14', '22-Mar-14', '23-Mar-14', '24-Mar-14', '25-Mar-14', '26-Mar-14', '27-Mar-14', '28-Mar-14', '29-Mar-14', '30-Mar-14', '31-Mar-14', '1-Apr-14', '2-Apr-14', '3-Apr-14', '4-Apr-14', '5-Apr-14', '6-Apr-14', '7-Apr-14', '8-Apr-14', '9-Apr-14',
'10-Apr-14', '11-Apr-14', '12-Apr-14', '15-Apr-14', '16-Apr-14', '17-Apr-14', '18-Apr-14']
>>>

strptime 这个函数是用来把日期转换成可以比较的日期时间对象。