如何将本地时间的datetime字符串转换为UTC时间的字符串?

我确信我以前做过这个,但找不到它,所以希望将来能帮助我(和其他人)做到这一点。

澄清:例如,如果我的本地时区(+10)是2008-09-17 14:02:00,我希望生成一个具有等效UTC时间的字符串:2008-09-17 04:02:00。

此外,从http://lucumr.pocoo.org/2011/7/15/eppur-si-muove/请注意,一般来说,这是不可能的,因为DST和其他问题没有从本地时间到UTC时间的唯一转换。


当前回答

还有一个使用pytz的例子,但是包含了localalize(),这帮了我大忙。

import pytz, datetime
utc = pytz.utc
fmt = '%Y-%m-%d %H:%M:%S'
amsterdam = pytz.timezone('Europe/Amsterdam')

dt = datetime.datetime.strptime("2012-04-06 10:00:00", fmt)
am_dt = amsterdam.localize(dt)
print am_dt.astimezone(utc).strftime(fmt)
'2012-04-06 08:00:00'

其他回答

怎么样——

time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime(seconds))

如果seconds为None,则将本地时间转换为UTC时间,否则将传入的时间转换为UTC时间。

在python3:

PIP安装python-dateutil

from dateutil.parser import tz

mydt.astimezone(tz.gettz('UTC')).replace(tzinfo=None) 

谢谢@rofly,从字符串到字符串的完整转换如下:

import time
time.strftime("%Y-%m-%d %H:%M:%S", 
              time.gmtime(time.mktime(time.strptime("2008-09-17 14:04:00", 
                                                    "%Y-%m-%d %H:%M:%S"))))

我对时间/日历功能的总结:

time.strptime 字符串——>元组(没有应用时区,所以匹配字符串)

time.mktime 本地时间元组——自epoch以来>秒(始终是本地时间)

time.gmtime seconds since epoch——UTC中的>元组

and

calendar.timegm tuple in UTC——> seconds since epoch

time.localtime 自epoch ->元组在本地时区的秒数

下面是一些常见的Python时间转换的总结。

有些方法以秒为单位,用(s)标记。可以使用显式公式,如ts = (d - epoch) / unit代替(感谢jfs)。

struct_time (UTC) → POSIX (s):calendar.timegm(struct_time) Naïve datetime (local) → POSIX (s):calendar.timegm(stz.localize(dt, is_dst=None).utctimetuple())(exception during DST transitions, see comment from jfs) Naïve datetime (UTC) → POSIX (s):calendar.timegm(dt.utctimetuple()) Aware datetime → POSIX (s):calendar.timegm(dt.utctimetuple()) POSIX → struct_time (UTC, s):time.gmtime(t)(see comment from jfs) Naïve datetime (local) → struct_time (UTC, s):stz.localize(dt, is_dst=None).utctimetuple()(exception during DST transitions, see comment from jfs) Naïve datetime (UTC) → struct_time (UTC, s):dt.utctimetuple() Aware datetime → struct_time (UTC, s):dt.utctimetuple() POSIX → Naïve datetime (local):datetime.fromtimestamp(t, None)(may fail in certain conditions, see comment from jfs below) struct_time (UTC) → Naïve datetime (local, s):datetime.datetime(struct_time[:6], tzinfo=UTC).astimezone(tz).replace(tzinfo=None)(can't represent leap seconds, see comment from jfs) Naïve datetime (UTC) → Naïve datetime (local):dt.replace(tzinfo=UTC).astimezone(tz).replace(tzinfo=None) Aware datetime → Naïve datetime (local):dt.astimezone(tz).replace(tzinfo=None) POSIX → Naïve datetime (UTC):datetime.utcfromtimestamp(t) struct_time (UTC) → Naïve datetime (UTC, s):datetime.datetime(*struct_time[:6])(can't represent leap seconds, see comment from jfs) Naïve datetime (local) → Naïve datetime (UTC):stz.localize(dt, is_dst=None).astimezone(UTC).replace(tzinfo=None)(exception during DST transitions, see comment from jfs) Aware datetime → Naïve datetime (UTC):dt.astimezone(UTC).replace(tzinfo=None) POSIX → Aware datetime:datetime.fromtimestamp(t, tz)(may fail for non-pytz timezones) struct_time (UTC) → Aware datetime (s):datetime.datetime(struct_time[:6], tzinfo=UTC).astimezone(tz)(can't represent leap seconds, see comment from jfs) Naïve datetime (local) → Aware datetime:stz.localize(dt, is_dst=None)(exception during DST transitions, see comment from jfs) Naïve datetime (UTC) → Aware datetime:dt.replace(tzinfo=UTC)

来源:taaviburns.ca

你可以用:

>>> from time import strftime, gmtime, localtime
>>> strftime('%H:%M:%S', gmtime()) #UTC time
>>> strftime('%H:%M:%S', localtime()) # localtime