在Python中，如何将自纪元以来的秒数转换为`datetime`对象？

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问题：在Python中，如何将自纪元以来的秒数转换为`datetime`对象？

所述time模块可使用秒因为历元进行初始化：

>>> import time
>>> t1=time.gmtime(1284286794)
>>> t1
time.struct_time(tm_year=2010, tm_mon=9, tm_mday=12, tm_hour=10, tm_min=19, 
                 tm_sec=54, tm_wday=6, tm_yday=255, tm_isdst=0)

有没有一种优雅的方法可以datetime.datetime以相同的方式初始化对象？

The time module can be initialized using seconds since epoch:

>>> import time
>>> t1=time.gmtime(1284286794)
>>> t1
time.struct_time(tm_year=2010, tm_mon=9, tm_mday=12, tm_hour=10, tm_min=19, 
                 tm_sec=54, tm_wday=6, tm_yday=255, tm_isdst=0)

Is there an elegant way to initialize a datetime.datetime object in the same way?

回答 0

datetime.datetime.fromtimestamp 如果您知道时区的话，您将产生与相同的输出 time.gmtime

>>> datetime.datetime.fromtimestamp(1284286794)
datetime.datetime(2010, 9, 12, 11, 19, 54)

要么

>>> datetime.datetime.utcfromtimestamp(1284286794)
datetime.datetime(2010, 9, 12, 10, 19, 54)

datetime.datetime.fromtimestamp will do, if you know the time zone, you could produce the same output as with time.gmtime

>>> datetime.datetime.fromtimestamp(1284286794)
datetime.datetime(2010, 9, 12, 11, 19, 54)

>>> datetime.datetime.utcfromtimestamp(1284286794)
datetime.datetime(2010, 9, 12, 10, 19, 54)

回答 1

纪元以来的秒数来datetime给strftime：

>>> ts_epoch = 1362301382
>>> ts = datetime.datetime.fromtimestamp(ts_epoch).strftime('%Y-%m-%d %H:%M:%S')
>>> ts
'2013-03-03 01:03:02'

Seconds since epoch to datetime to strftime:

>>> ts_epoch = 1362301382
>>> ts = datetime.datetime.fromtimestamp(ts_epoch).strftime('%Y-%m-%d %H:%M:%S')
>>> ts
'2013-03-03 01:03:02'

回答 2

从文档中，从纪元以来的几秒钟内获取时区感知日期时间对象的推荐方法是：

Python 3：

from datetime import datetime, timezone
datetime.fromtimestamp(timestamp, timezone.utc)

Python 2，使用pytz：

from datetime import datetime
import pytz
datetime.fromtimestamp(timestamp, pytz.utc)

From the docs, the recommended way of getting a timezone aware datetime object from seconds since epoch is:

Python 3:

from datetime import datetime, timezone
datetime.fromtimestamp(timestamp, timezone.utc)

Python 2, using pytz:

from datetime import datetime
import pytz
datetime.fromtimestamp(timestamp, pytz.utc)

回答 3

请注意，datetime.datetime。fromtimestamp（时间戳）和。utcfromtimestamp（时间戳）在1970年1月1日之前的日期上在Windows上失败，而负的unix时间戳似乎在基于unix的平台上起作用。文档说：

“ 如果时间戳不在平台C gmtime（）函数支持的值范围内，则可能会引发ValueError。通常将其限制在1970年至2038年之间 ”

另请参见Issue1646728

Note that datetime.datetime.fromtimestamp(timestamp) and .utcfromtimestamp(timestamp) fail on windows for dates before Jan. 1, 1970 while negative unix timestamps seem to work on unix-based platforms. The docs say this:

“This may raise ValueError, if the timestamp is out of the range of values supported by the platform C gmtime() function. It’s common for this to be restricted to years in 1970 through 2038“

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