[Python-ideas] bool(datetime.time(0, 0))

[M.-A. Lemburg]

Alexander Belopolsky wrote:
> On Mon, May 7, 2012 at 11:32 AM, Antoine Pitrou <solipsis at pitrou.net> wrote:
>> Well, less occasional puzzlement is an improvement in itself.
>> Unintuitive behaviour is always a risk for software quality.
> 
> I don't find the current behavior unintuitive.  It is common to
> represent time of day as an integer (number of minutes or seconds
> since midnight) or as a float (fraction of the 24-hour day).  In these
> cases one gets bool(midnight) -> False as an artifact of the
> representation.

In Python 2.x, the slot used by bool() is called nb_nonzero, which
returns 1/0 depending on whether a value is considered zero or not.

This makes it quite natural for any special object representing a
value akin to zero in its domain to be false.

In Python 3.x, nb_nonzero was renamed to nb_bool without really
paying attention to the fact that many types implemented the original
meaning instead of a notion of boolean value, so I guess we'll just
have to live with it, unless we want to introduce yet another
subtle difference between Python 2.x and 3.x.

-- 
Marc-Andre Lemburg
eGenix.com

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