[Python-Dev] PEP 410 (Decimal timestamp): the implementation is ready for a review (original) (raw)

Barry Warsaw barry at python.org
Wed Feb 15 14:36:06 CET 2012

On Feb 15, 2012, at 10:23 AM, Nick Coghlan wrote:

What should timedelta.totalseconds() return to avoid losing nanosecond precision? How should this be requested when calling the API?

See, I have no problem having this method return a Decimal for high precision values. This preserves the valuable abstraction of timedeltas, but also provides a useful method for interoperability.

The core "timestamp" abstraction is "just a number" that (in context) represents a certain number of seconds. decimal.Decimal qualifies. datetime.timedelta doesn't - it's a higher level construct that makes the semantic context explicit (and currently refuses to interoperate with other values that are just numbers).

Right, but I think Python should promote the abstraction as the way to manipulate time-y data. Interoperability is an important principle to maintain, but IMO the right way to do that is to improve datetime and timedelta so that lower-level values can be extracted from, and added to, the higher-level abstract types.

I think there are quite a few opportunities for improving the interoperability of datetime and timedelta, but that shouldn't be confused with bypassing them.

Cheers, -Barry -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 836 bytes Desc: not available URL: <http://mail.python.org/pipermail/python-dev/attachments/20120215/53e1333f/attachment.pgp>

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