[Python-Dev] datetime nanosecond support (ctd?)

[matthieu bec]

Agreed with Antoine, strftime/strptime are somewhat different concerns.
Doesn't mean thay cannot be fixed at the same time but it's a bit a 
separate.

I'm not sure this thread / discussion has reached critical mass yet, 
meanwhile I was looking at what was involved and came up with this 
half-baked patch - by no way meant to be complete or correct, but rather 
get a feel to it.

I can't help thinking this is much more involved than I first expected, 
and what I try to achieve should be reasonably simple.

Stepping back a little, I wonder if the datetime module is really the 
right location, that has constructor(year, month, day, ..., second, 
microsecond) - with 0<ms<999999, no millis. adding 0<ns<999 would seem 
quite ugly, in fact nothing looks quite right.

datetime seems to be dealing with 'calendar time' stuff - and to some 
extent, maybe, shouldn't concern itself so much with fraction of seconds.

I'm pondering now if the 'time' module that seems to be dealing with 
'computer clock time' wouldn't be a better target to introduce 
struct_timespec and the like.

I'd be curious to hear back from this list, if this deserves more 
investigation or what might be a better way to go.

Regards,
Matthieu


On 12/11/2014 11:46 AM, Antoine Pitrou wrote:
> On Thu, 11 Dec 2014 13:43:05 -0600
> Skip Montanaro <skip.montanaro at gmail.com> wrote:
>> On Thu, Dec 11, 2014 at 1:23 PM, Antoine Pitrou <solipsis at pitrou.net> wrote:
>>> I think strftime / strptime support is a low-priority concern on this
>>> topic, and can probably be discussed independently of the core
>>> nanosecond support.
>>
>> Might be low-priority, but with %f support as a template, supporting
>> something to specify nanoseconds should be pretty trivial. The hardest
>> question will be to convince ourselves that we aren't choosing a
>> format code which some other strftime/strptime implementation is
>> already using.
>>
>> In addition, ISTR that one of the use cases was analysis of datetime
>> data generated by other applications which has nanosecond resolution.
>
> One of the use cases is to deal with OS-generated timestamps without
> losing information. As long as you don't need to represent or parse
> those timestamps, strptime / strftime don't come into the picture.
>
> Regards
>
> Antoine.
> _______________________________________________
> Python-Dev mailing list
> Python-Dev at python.org
> https://mail.python.org/mailman/listinfo/python-dev
> Unsubscribe: https://mail.python.org/mailman/options/python-dev/mdcb808%40gmail.com
>


-- 
Matthieu Bec                GMTO Corp
cell : +1 626 425 7923      251 S Lake Ave, Suite 300
phone: +1 626 204 0527      Pasadena, CA 91101
-------------- next part --------------
A non-text attachment was scrubbed...
Name: datetime_ns.patch
Type: text/x-patch
Size: 39257 bytes
Desc: not available
URL: <http://mail.python.org/pipermail/python-dev/attachments/20141216/d47be824/attachment.bin>