[Python-3000] None in Comparisons
mal at egenix.com
Tue Nov 11 15:21:03 CET 2008
On 2008-11-11 15:07, Barry Warsaw wrote:
> On Nov 11, 2008, at 8:54 AM, M.-A. Lemburg wrote:
>> On 2008-11-11 14:28, Antoine Pitrou wrote:
>>> M.-A. Lemburg <mal <at> egenix.com> writes:
>>>> Why was the special case for None being "smaller" than all other
>>>> objects in Python removed from Python 3.0 ? (see object.c in Py2.x)
>>> Because ordered comparisons (<, <=, >, >=) are much stricter in 3.0
>>> than in 2.x.
>>> In practice, ordered comparisons which don't have an obvious,
>>> intuitive meaning
>>> now raise a TypeError (such as comparing a number and a string).
>> That's fine. I'm just talking about the special case for None that
>> has existed in Python for years - and for a good reason.
> How hard is it to implement your own "missing" object which has the
> desired semantics? Why should something as fundamental as None have it?
Because None is already special, has had this feature for a very
long time and there's no apparent reason to move the feature to
some other special object.
Also, having each module or project invent its own NULL-like
object will not make things better for anyone, it would only
introduce new problems.
I don't see any benefit from the removal of the special property
of None in Python 3.0.
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