[Tutor] could somebody please explain...

[Danny Yoo]

> Also, I found something that I can’t get my mind around. It is part of the
> time/date protocols. I’ve not seen it anywhere else.
>
> Datetime(year=blah, blah, blah).date/time()
>
> datetime(2013,3,6).date() #returns…
> datetime.date(2013,3,6)
>
> datetime(2013,3,6).time() #returns…
> datetime.time(0,0)
>
> This is one of the weirder things I’ve run across. Is this allowed/needed in
> other functions/classes, or is it a datetime thing only?


Can you say more about what you expect?  It may help to be very
explicit, even if it seems silly.  The problem with talking with
experienced tutors and programmers is that our perspective has warped
slightly from extended exposure.  :P  So we may need a bit of hinting
to tell what you're referring to by weirdness.


The datetime library, if I recall correctly, combines two things: the
date part, and the time part, each which are otherwise treated
separately.  It's a composite object.

    https://docs.python.org/2/library/datetime.html#datetime-objects

When we construct a datetime.datetime, at the very least we need to
provide its year, month, and day, but the other "time" components of
it are optional.  That's what the documentation is trying to say when
it wraps the arguments in braces here:

    https://docs.python.org/2/library/datetime.html#datetime.datetime

If you don't provide the time-related arguments, I think it assumes
that those components are zeroed out.