将datetime.date转换为UTC时间戳 [英] Converting datetime.date to UTC timestamp in Python
问题描述
。以下代码无效:
>>> d = datetime.date(2011,01,01)
>>> datetime.datetime.utcfromtimestamp(time.mktime(d.timetuple()))
datetime.datetime(2010,12,31,23,0)
将日期对象首先转换为datetime也没有帮助。我尝试了这个链接的示例,但是:
from pytz import utc,timezone
from datetime import datetime
from time import mktime
input_date = datetime( year = 2011,month = 1,day = 15)
现在或者:
mktime(utc.localize(input_date).utctupuple())
或
mktime(timezone('US / Eastern'))localize(input_date ).utctimetuple())
正常工作。
所以一般的问题:根据UTC,如何从日期转换为秒数?
如果 d = date(2011,1,1)
在UTC中:
> ;>> from datetime import datetime,date
>>>>进口日历
>>>> timestamp1 = calendar.timegm(d.timetuple())
>>> datetime.utcfromtimestamp(timestamp1)
datetime.datetime(2011,1,1,0,0)
如果 d
在本地时区:
>> ;>进口时间
>>>> timestamp2 = time.mktime(d.timetuple())#请勿使用UTC DATE
>>> datetime.fromtimestamp(timestamp2)
datetime.datetime(2011,1,1,0,0)
timestamp1
和 timestamp2
可能会有所不同,如果本地时区的午夜与UTC的午夜不一样的时间
mktime()
如果 d $ c $可能会返回错误的结果c>对应于模糊的本地时间(例如,在DST转换期间)或者如果
d
是一个过去(未来)的日期,当utc偏移量可能不同和 C mktime()
无法访问 tz数据库在给定的平台上。您可以使用 pytz
模块(例如,通过 tzlocal)。 get_localzone()
)以访问所有平台上的tz数据库。另外, utcfromtimestamp()
可能会失败,并且 mktime()
可能会返回非POSIX时间戳,如果right
时区使用。
转换 datetime.date
表示日期的对象,不含 calendar.timegm()
:
DAY = 24 * 60 * 60#POSIX天数(精确值)
timestamp =(utc_date.toordinal() - date(1970,1,1).toordinal())* DAY
timestamp =(utc_date - date(1970,1,1))。days * DAY
我可以根据UTC得到一个从时代转换成秒的日期吗?
转换 datetime.datetime
(not datetime.date
)对象已经表示UTC的时间到相应的POSIX时间戳(a $ code> float )。
Python 3.3 +
timestamp = dt.replace(tzinfo = timezone.utc).timestamp()
注意: timezone.utc
明确地否则 .timestamp()
假定您的天真的datetime对象在本地时区。
Python 3(< 3.3)
从 datetime.utcfromtimestamp()
:
有没有从datetime实例获取时间戳的方法,
,而对应于datetime实例的POSIX时间戳可以是
,容易计算如下。对于一个天真的dt:
timestamp =(dt - datetime(1970,1,1) )/ timedelta(seconds = 1)
timestamp =(dt - datetime(1970,1,1,tzinfo = timezone.utc ))/ timedelta(seconds = 1)
有趣的是:时代与时间的关系关于什么时间?和已经有多少秒?
另请参见: datetime需要一个epoch方法
Python 2
Python 2的代码:
timestamp =(dt - datetime(1970,1,1))。total_seconds()
其中 timedelta.total_seconds()
相当于(td.microseconds +(td.seconds + td
示例
从__future__进口部门
from datetime import datetime,timedelta
def totimestamp(dt,epoch = datetime(1970,1,1)):
td = dt - epoch
#return td.total_seconds()
return(td.microseconds +(td.seconds + td.days * 86400)* 10 ** 6)/ 10 ** 6
now = datetime.utcnow ()
打印现在
打印totimestamp(现在)
当心浮点问题。
输出
2012-01-08 15:34:10.022403
1326036850.02
如何将意义 datetime
对象转换为POS IX时间戳
assert dt.tzinfo不为None,dt.utcoffset()不为None
timestamp = dt。时间戳()#Python 3.3+
在Python 3:
from datetime import datetime,timedelta,timezone
epoch = datetime(1970,1,1,tzinfo = timezone.utc)
时间戳=(dt - epoch)/ timedelta(seconds = 1)
integer_timestamp =(dt - epoch)// timedelta(seconds = 1)
在Python 2上:
#utc time = local time - utc offset
utc_naive = dt.replace(tzinfo = None) - dt.utcoffset()
timestamp =(utc_naive - datetime(1970,1,1))。total_seconds()
I am dealing with dates in Python and I need to convert them to UTC timestamps to be used inside Javascript. The following code does not work:
>>> d = datetime.date(2011,01,01)
>>> datetime.datetime.utcfromtimestamp(time.mktime(d.timetuple()))
datetime.datetime(2010, 12, 31, 23, 0)
Converting the date object first to datetime also does not help. I tried the example at this link from, but:
from pytz import utc, timezone
from datetime import datetime
from time import mktime
input_date = datetime(year=2011, month=1, day=15)
and now either:
mktime(utc.localize(input_date).utctimetuple())
or
mktime(timezone('US/Eastern').localize(input_date).utctimetuple())
does work.
So general question: how can I get a date converted to seconds since epoch according to UTC?
If d = date(2011, 1, 1)
is in UTC:
>>> from datetime import datetime, date
>>> import calendar
>>> timestamp1 = calendar.timegm(d.timetuple())
>>> datetime.utcfromtimestamp(timestamp1)
datetime.datetime(2011, 1, 1, 0, 0)
If d
is in local timezone:
>>> import time
>>> timestamp2 = time.mktime(d.timetuple()) # DO NOT USE IT WITH UTC DATE
>>> datetime.fromtimestamp(timestamp2)
datetime.datetime(2011, 1, 1, 0, 0)
timestamp1
and timestamp2
may differ if midnight in the local timezone is not the same time instance as midnight in UTC.
mktime()
may return a wrong result if d
corresponds to an ambiguous local time (e.g., during DST transition) or if d
is a past(future) date when the utc offset might have been different and the C mktime()
has no access to the tz database on the given platform. You could use pytz
module (e.g., via tzlocal.get_localzone()
) to get access to the tz database on all platforms. Also, utcfromtimestamp()
may fail and mktime()
may return non-POSIX timestamp if "right"
timezone is used.
To convert datetime.date
object that represents date in UTC without calendar.timegm()
:
DAY = 24*60*60 # POSIX day in seconds (exact value)
timestamp = (utc_date.toordinal() - date(1970, 1, 1).toordinal()) * DAY
timestamp = (utc_date - date(1970, 1, 1)).days * DAY
How can I get a date converted to seconds since epoch according to UTC?
To convert datetime.datetime
(not datetime.date
) object that already represents time in UTC to the corresponding POSIX timestamp (a float
).
Python 3.3+
timestamp = dt.replace(tzinfo=timezone.utc).timestamp()
Note: It is necessary to supply timezone.utc
explicitly otherwise .timestamp()
assume that your naive datetime object is in local timezone.
Python 3 (< 3.3)
From the docs for datetime.utcfromtimestamp()
:
There is no method to obtain the timestamp from a datetime instance, but POSIX timestamp corresponding to a datetime instance dt can be easily calculated as follows. For a naive dt:
timestamp = (dt - datetime(1970, 1, 1)) / timedelta(seconds=1)
And for an aware dt:
timestamp = (dt - datetime(1970,1,1, tzinfo=timezone.utc)) / timedelta(seconds=1)
Interesting read: Epoch time vs. time of day on the difference between What time is it? and How many seconds have elapsed?
See also: datetime needs an "epoch" method
Python 2
To adapt the above code for Python 2:
timestamp = (dt - datetime(1970, 1, 1)).total_seconds()
where timedelta.total_seconds()
is equivalent to (td.microseconds + (td.seconds + td.days * 24 * 3600) * 10**6) / 10**6
computed with true division enabled.
Example
from __future__ import division
from datetime import datetime, timedelta
def totimestamp(dt, epoch=datetime(1970,1,1)):
td = dt - epoch
# return td.total_seconds()
return (td.microseconds + (td.seconds + td.days * 86400) * 10**6) / 10**6
now = datetime.utcnow()
print now
print totimestamp(now)
Beware of floating-point issues.
Output
2012-01-08 15:34:10.022403
1326036850.02
How to convert an aware datetime
object to POSIX timestamp
assert dt.tzinfo is not None and dt.utcoffset() is not None
timestamp = dt.timestamp() # Python 3.3+
On Python 3:
from datetime import datetime, timedelta, timezone
epoch = datetime(1970, 1, 1, tzinfo=timezone.utc)
timestamp = (dt - epoch) / timedelta(seconds=1)
integer_timestamp = (dt - epoch) // timedelta(seconds=1)
On Python 2:
# utc time = local time - utc offset
utc_naive = dt.replace(tzinfo=None) - dt.utcoffset()
timestamp = (utc_naive - datetime(1970, 1, 1)).total_seconds()
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