[Python-ideas] Date/time literals

[Masklinn]

On 2010-05-30, at 03:49 , Chris Rebert wrote:
> On Sat, May 29, 2010 at 6:05 PM, Marcos Bonci <marcos.bonci at gmail.com> wrote:
>> Hi!
>> I've been working a lot with date/time variables lately, and maybe it's just
>> me, and
>> maybe I just don't get it yet, but it sure doesn't feel like there's
>> one-and-only-one
>> elegant, obvious way to work with them. Feels like working with strings in
>> C.
> 
> Reading the rest of your post, it sounds like you're unaware of the
> fairly nice API of the `datetime` std lib module:
> http://docs.python.org/library/datetime.html
> 
> IMO, it's pretty nice to work with; although it is annoying that some
> operations can only be done using the more primitive `time` or
> `calendar` modules. Patches are probably welcome; perhaps I should
> consider trying to write one.

datetime does have a bunch of issues and limitations which I believe soon
become harmful when doing serious date/calendaring works (which I don't
claim to do, but I've seen colleagues in serious trouble due to both
personal lack of knowledge in the field and issues with datetime itself):
it only supports a gregoriany calendar for instance, it's horrendous
in dealing with timezones, some methods are pretty much broken, 
constructor refuses "24" as an hour value, blows up on positive leap
seconds)…

See the following resources for issues with datetime:
http://blog.mfabrik.com/2008/06/30/relativity-of-time-shortcomings-in-python-datetime-and-workaround/
http://www.enricozini.org/2009/debian/using-python-datetime/

Libraries built over datetime:
http://labix.org/python-dateutil
http://pytz.sourceforge.net/ [1]


[1] note that as mentioned in the first blog post, datetime apparently
has issues re querrying tz objects, so it's generally suggested to work
with utc-only datetime objects and let the timezone stuff to direct 
pytz calls.