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[Python-Dev] PEP: New timestamp formats
Gregory P. Smithgreg at krypto.org
Fri Feb 3 22:09:22 CET 2012
Why is the PEP promoting the float type being used as the default on thenew-in-3.3 APIs that were added explicitly to provide nanosecond levelresolution that cannot be represented by a float?The *new* APIs should default to the high precision return value (be thatdatetime/timedelta or decimal).-gpsOn Fri, Feb 3, 2012 at 11:32 AM, Jeffrey Yasskin <jyasskin at gmail.com> wrote:> On Fri, Feb 3, 2012 at 11:17 AM, Antoine Pitrou <solipsis at pitrou.net>> wrote:> > On Fri, 3 Feb 2012 11:04:14 -0800> > Jeffrey Yasskin <jyasskin at gmail.com> wrote:> >> On Thu, Feb 2, 2012 at 4:59 PM, Nick Coghlan <ncoghlan at gmail.com>> wrote:> >> > datetime.datetime> >> >> >> > - real problem with the idea is that not all timestamps can be easily> >> > made absolute (e.g. some APIs may return "time since system started"> >> > or "time since process started")> >>> >> I think this is an argument for returning the appropriate one of> >> datetime or timedelta from all of these functions: users need to keep> >> track of whether they've got an absolute time, or an offset from an> >> unspecified starting point, and that's a type-like distinction.> >> > Keep in mind timedelta has a microsecond resolution. The use cases> > meant for the PEP imply nanosecond resolution (POSIX' clock_gettime(),> > for example).>> Yes, I think someone had noted that datetime and timedelta would need> to be extended to support nanosecond resolution.>> >> A plain number of seconds is superficially simpler, but it forces more> >> complexity onto the user, who has to track what that number> >> represents.> >> > If all you are doing is comparing timestamps (which I guess is most of> > what people do with e.g. st_mtime), a number is fine.>> Sure. I don't think the argument for datetime is totally convincing,> just that it's stronger than the PEP currently presents.>> > If you want the current time and date in a high-level form, you can> > already use datetime.now() or datetime.utcnow() (which "only" has> > microsecond resolution as well :-)). We don't need another way to spell> > it.>> Whoops, yes, there's no need to extend time() to return a datetime.> _______________________________________________> Python-Dev mailing list>Python-Dev at python.org>http://mail.python.org/mailman/listinfo/python-dev> Unsubscribe:>http://mail.python.org/mailman/options/python-dev/greg%40krypto.org>-------------- next part --------------An HTML attachment was scrubbed...URL: <http://mail.python.org/pipermail/python-dev/attachments/20120203/2505e53a/attachment.html>
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