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

Victor Stinner victor.stinner at gmail.com
Wed Feb 15 14:14:54 CET 2012

2012/2/15 "Martin v. Löwis" <martin at v.loewis.de>:

I agree with Barry here (despite having voiced support for using Decimal before): datetime.datetime is the right data type to represent time stamps. If it means that it needs to be improved before it can be used in practice, then so be it - improve it.

Decimal and datetime.datetime are not necessary exclusive options. Using the API proposed in the PEP, we can add the Decimal type today, then improve datetime.datetime API, and finally add also datetime.datetime type.

Such compromise would solve the unspecified starting date issue: an exception would be raised if the timestamp has an unspecified timestamp. In such case, you can still get the timestamp as a Decimal object with nanosecond resolution. Or we may add support of datetime and Decimal today, even if datetime only support microsecond, and improve datetime later to support nanosecond.

It looks like there are use cases for Decimal and datetime, both are useful. At least, datetime has a nice object API related to time, whereas Decimal requires functions from other modules. I don't know yet if one type is enough to handle all use cases.

I wrote a patch to demonstrate that my internal API can be extended (store more information for new types like datetime.datetime) to add new types later, without touching the public API (func(timestamp=type)). See timestamp_datetime.patch attached to the issue #13882 (the patch is now outside, I can update it if you would like to).

For example:

Victor

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