[Python-Dev] PEP 3144 review.

[Mark Dickinson]

On Wed, Sep 30, 2009 at 10:52 AM, Paul Moore <p.f.moore at gmail.com> wrote:
> 2009/9/30 Mark Dickinson <dickinsm at gmail.com>:
>> Please could someone who understands the uses of IPNetwork better than
>> I do explain why the following wouldn't be a significant problem, if __eq__
>> and __hash__ were modified to disregard the .ip attribute as suggested:
>>
>>>>> linus = IPv4Network('172.16.200.1/24')
>>>>> snoopy = IPv4Network('172.16.200.3/24')
>>>>> fqdn = {linus: 'linus.peanuts.net', snoopy: 'snoopy.peanuts.net'}
>>>>> fqdn[linus]  # expecting 'linus.peanuts.net'
>> 'snoopy.peanuts.net'
>
> I certainly don't understand IPv4Network better than you :-) But that
> just looks wrong to me - linus and snoopy are hosts not networks, so
> making them IPv4Network classes seems wrong. I'd instinctively make
> them IPv4Address objects (which, I believe, would work).

Okay, so maybe this is an abuse of IPv4Network.  But I'd (mis?)understood
that the retention of the .ip attribute was precisely a convenience to allow
this sort of use.  If not, then what's it for?  I've read the PEP and almost
all of this thread, but I can't help feeling I'm still missing something.  If
someone could point out the obvious to me I'd be grateful.

I don't have any opinion on whether the ip attribute should be retained
or not; but retaining it *and* ignoring it in comparisons just seems a
bit odd.

Mark