如何将日期时间转换为正确的格式以使用 pytz 模块

Question

如果我在这样的列中有一堆日期时间（UTC）：

63058    01/22/2018 11:00:00
63059    01/22/2018 12:00:00
63060    01/22/2018 13:00:00
Name: date, Length: 63061, dtype: object

或者这个：

DatetimeIndex(['2007-12-21 17:00:00', '2007-12-21 18:00:00',
           '2007-12-21 19:00:00', '2007-12-21 20:00:00',
           '2007-12-21 21:00:00', '2007-12-23 20:00:00',
           '2007-12-23 22:00:00', '2007-12-23 23:00:00',
           '2007-12-24 00:00:00', '2007-12-24 01:00:00',
           ...
           '2018-01-22 04:00:00', '2018-01-22 05:00:00',
           '2018-01-22 06:00:00', '2018-01-22 07:00:00',
           '2018-01-22 08:00:00', '2018-01-22 09:00:00',
           '2018-01-22 10:00:00', '2018-01-22 11:00:00',
           '2018-01-22 12:00:00', '2018-01-22 13:00:00'],
          dtype='datetime64[ns]', length=63061, freq=None)

如何将整个（列表或系列）转换为这种格式：

datetime(2016, 1, 24, 18, 0, 0, tzinfo=utc)

因为我需要使用pytz 模块将UTC 转换为东部时间。

当我将astimezone().strftime() 与我的原始数据格式一起使用时，我收到此错误：AttributeError: 'Index' object has no attribute 'astimezone'。 This is what I originally wanted to do，但现在我遇到了这个问题。谢谢。

Answer 1

您可以定义一个函数来转换其中一种字符串表示形式，如下所示：

from datetime import datetime
import pytz

def date_from_string(s):
    "Convert ``s`` from a string to a datetime object in the UTC time zone."
    dt = datetime.strptime(s, '%Y-%m-%d %H:%M:%S')
    return dt.replace(tzinfo=pytz.utc)

然后你可以在你的构造函数中使用map

DatetimeIndex(map(date_from_string, [
       '2007-12-21 17:00:00', '2007-12-21 18:00:00',
       '2007-12-21 19:00:00', '2007-12-21 20:00:00',
       '2007-12-21 21:00:00', '2007-12-23 20:00:00',
       '2007-12-23 22:00:00', '2007-12-23 23:00:00',
       '2007-12-24 00:00:00', '2007-12-24 01:00:00',
       ...
       '2018-01-22 04:00:00', '2018-01-22 05:00:00',
       '2018-01-22 06:00:00', '2018-01-22 07:00:00',
       '2018-01-22 08:00:00', '2018-01-22 09:00:00',
       '2018-01-22 10:00:00', '2018-01-22 11:00:00',
       '2018-01-22 12:00:00', '2018-01-22 13:00:00']),
      dtype='datetime64[ns]', length=63061, freq=None)

文档有更多信息：

datetime.strptime(..):https://docs.python.org/2/library/datetime.html#strftime-and-strptime-behavior

map(..):https://docs.python.org/2/library/functions.html#map