[Python-Dev] proposal: add basic time type to the standard library (original) (raw)

Jim Fulton jim@zope.com
Tue, 26 Feb 2002 09:04:27 -0500

Guido van Rossum wrote:

> http://effbot.org/ideas/time-type.htm > > I can produce PEP and patch if necessary. Yes, a PEP, please! Jim Fulton has been asking for this for a long time too. His main requirement is that timestamp objects are small, both in memory and as pickles, because Zope keeps a lot of these around.

I also need time-zone support.

They are currently represented either as long ints (with a little under 64 bits) or as 8-byte strings.

ZODB has a TimeStamp type that uses a 32-bit unsigned integer to store year, month,, day, hour, and minute in a way that makes it dirt simple to extract a component. It uses a 32-bit integer to store seconds in units of 60/2**32 seconds.

This type isn't appropriate for general use because it only allows dates later than Dec 31, 1899.

A dedicated timestamp object could be smaller than that.

A type that only needed minute precision could easily be expressed with 32-bits. Of course, the two-word object overhead makes the difference between 32-bits and 64-bits rather unexciting.

Your idea of a base type (which presumably standarizes at least one form of representation) sounds like a breakthrough that can help satisfy different other needs.

I agree.

Jim

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