On Sat, May 29, 2010 at 6:05 PM, Marcos Bonci <marcos.bonci@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.
So I was thinking, have date and time literals ever been seriously discussed anywhere in these discussion lists? (If so, I apologize in advance for reviving this subject.) Is there any chance we could ever see date/time literals in Python?
Well, the datetime module does appear to already be written in C, so that'd be one less hurdle. I wasn't able to find a prior post on the exact subject; perhaps someone else will.
Perhaps as a top-level abstraction itself, or as a subclass of numbers.Number, or even as common float or int (by adding attributes regarding specific properties of a number's date/time interpretation, e.g. "<2010-12-31>.incr_month(2) == <2011-02-28>" -- just an example though, i don't really think this exact method would be practical).
The `datetime` module already provides nice and more typesafe abstractions; purposefully conflating date/times with plain numbers is not a good idea, imo. <snip>
Very often the "time elapsed" value is what we really want (or at least the absolute difference between two values, which is of course easier to find in this form), and besides being more compact and flexible, no functionality is lost.
datetime.timedelta: http://docs.python.org/library/datetime.html#timedelta-objects
I guess the most controversial point here would be the meaning of arithmetic operations between dates (or the very validity of such operations).
Already defined and accepted as valid: datetime.date, "Supported operations" http://docs.python.org/library/datetime.html#date-objects <snip>
So, what do you guys think? I'd love to hear others' opinions, even if it's just for me to understand what I got wrong and see the obvious way that's already there
I think the classes in the `datetime` module are the nice "missing" API that you're looking for, and that there's not enough of a gain to justify complicating the language by adding literals for them and making them built-in types. Cheers, Chris -- http://blog.rebertia.com