On Fri, Jan 19, 2018 at 12:53 PM, Paul G <[email protected]> wrote: > That said, it's still somewhat glaring in its absence. Thinking about it, > though, I think it's not at all unreasonable to include a zoneinfo *parser* > into Python's `datetime` library, something similar to `dateutil.tz.tzfile`
A variant of tzfile is in fact included, but buried in the datetime tester. Unfortunately, binary tz files distributed with many UNIX-like OSes do not preserve enough information to implement a high quality Python tzinfo subclass. The missing information is the breakdown of utcoffset into standard offset and dst. The tz files only store DST as a boolean and in the rare cases when DST differs from 1 hour, it is impossible to accurately figure out the .dst() timedelta. If we go to the trouble of implementing a Zoneinfo parser, I suggest that we also include a parser for the raw IANA files that can extract the DST timedelta information from the "SAVE" field. Note that I started toying with some related ideas at <https://github.com/abalkin/tz>. _______________________________________________ Datetime-SIG mailing list [email protected] https://mail.python.org/mailman/listinfo/datetime-sig The PSF Code of Conduct applies to this mailing list: https://www.python.org/psf/codeofconduct/
