如何将 datetime.time 从 UTC 转换为不同的时区?

2022-01-16 00:00:00 python datetime timezone

问题描述

我有一个保存时间的变量，它是 UTC 中的 datetime.time 类型，我希望它转换为其他时区.

I have variable which holds time which is of type datetime.time in UTC, I wanted it to convert to some other timezone.

我们可以转换 datetime.datetime 实例中的时区，如此链接所示 - 如何在 Python 中将本地时间转换为 UTC?.我无法弄清楚如何在 datetime.time 实例中转换时区.我不能使用 astimezone 因为 datetime.time 没有这个方法.

we can convert timezones in datetime.datetime instance as shown in this SO link - How do I convert local time to UTC in Python?. I am not able to figure out how to convert timezones in datetime.time instances. I can't use astimezone because datetime.time doesn't have this method.

例如:

>>> t = d.datetime.now().time()
>>> t
datetime.time(12, 56, 44, 398402)
>>>

我需要 UTC 格式的t".

I need 't' in UTC format.

解决方案

有四种情况:

  1. input datetime.time 设置了 tzinfo (例如 OP 提到 UTC)
  1. input datetime.time has tzinfo set (eg OP mentions UTC)
  1. 输出为非天真的时间
  2. 作为原始时间输出(tzinfo 未设置)

  • 输入 datetime.time 未设置 tzinfo

    1. 输出为非天真的时间
    2. 作为原始时间输出(tzinfo 未设置)

    • 正确答案需要使用 datetime.datetime.timetz() 函数，因为 datetime.time 不能通过调用 构建为非朴素时间戳>localize() 或 astimezone() 直接.

    The correct answer needs to make use of datetime.datetime.timetz() function because datetime.time cannot be built as a non-naive timestamp by calling localize() or astimezone() directly.

    from datetime import datetime, time
import pytz

def timetz_to_tz(t, tz_out):
    return datetime.combine(datetime.today(), t).astimezone(tz_out).timetz()

def timetz_to_tz_naive(t, tz_out):
    return datetime.combine(datetime.today(), t).astimezone(tz_out).time()

def time_to_tz(t, tz_out):
    return tz_out.localize(datetime.combine(datetime.today(), t)).timetz()

def time_to_tz_naive(t, tz_in, tz_out):
    return tz_in.localize(datetime.combine(datetime.today(), t)).astimezone(tz_out).time()

    基于 OP 要求的示例:

    Example based on OP requirement:

    t = time(12, 56, 44, 398402)
time_to_tz(t, pytz.utc) # assigning tzinfo= directly would not work correctly with other timezones

datetime.time(12, 56, 44, 398402, tzinfo=<UTC>)

    如果需要简单的时间戳:

    In case naive timestamp is wanted:

    time_to_tz_naive(t, pytz.utc, pytz.timezone('Europe/Berlin'))

datetime.time(14, 56, 44, 398402)

    time() 实例已经 tzinfo 设置的情况更容易，因为 datetime.combine 从传递的参数中提取 tzinfo, 所以我们只需要转换成 tz_out.

    The cases where the time() instance has already tzinfo set are easier because datetime.combine picks up the tzinfo from the passed parameter, so we just need to convert to tz_out.

    相关文章