[Python-Dev] ISO 8601 durations and datetime.timedelta (original) (raw)

Alexander Belopolsky alexander.belopolsky at gmail.com
Fri Mar 28 18:42:48 CET 2014

On Fri, Mar 28, 2014 at 1:13 PM, Skip Montanaro <skip at pobox.com> wrote:

Given that the timedelta has more than "a month's" worth of days, how would you describe it using the ISO8601 duration notation without referencing a specific point in time? Conversely, given your example, "P3Y6M4DT12H30M5S", how would you convert that into a timedelta without knowing which exact years and months this duration refers to? Timedelta objects are very precise beasts, which is almost certainly why they don't support "years" and "months" args in their constructors.

So why would they need to support them in str()? We could make str(timedelta(days=369, hours=12, minutes=30, seconds=5)) return "P369DT12H30M5S", but that would hardly be an improvement over

print timedelta(days=369, hours=12, minutes=30, seconds=5) 369 days, 12:30:05

and I don't think ISO 8601 allows for negative durations, so it gives us little guidance for the other issue either.

My preference would be to leave strict ISO 8601 compliance to 3rd party libraries. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.python.org/pipermail/python-dev/attachments/20140328/9092842a/attachment-0001.html>

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