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[Python-Dev] PEP 3144: IP Address Manipulation Library for the Python Standard Library

Peter Moody peter at hda3.com
Thu Aug 20 00:01:42 CEST 2009 
On Wed, Aug 19, 2009 at 2:44 PM, Nick Coghlan<ncoghlan at gmail.com> wrote:
> Peter Moody wrote:
>> you can't set them directly, if that's what you mean.
>>
>>>>> import ipaddr
>>>>> o = ipaddr.IPv4Network('1.1.1.0/24')
>>>>> o.broadcast
>> IPv4Address('1.1.1.255')
>>>>> o.network
>> IPv4Address('1.1.1.0')
>>>>> o.broadcast = ipaddr.IPv4Address('1.1.1.127')
>> Traceback (most recent call last):
>>   File "<stdin>", line 1, in <module>
>> AttributeError: can't set attribute
>>>>> o.prefixlen = 25
>>>>> o.broadcast
>> IPv4Address('1.1.1.127')
>
> IPAddress instances should definitely be hashable, but as long as
> "prefixlen" is mutable, IPNetwork instances should *not* be hashable,
> since their value can change.
>
> If prefixlen was made read only, then IPNetwork instances could also be
> made hashable. In that case, changing the prefix length would then have
> to be done by creating a new instance.

ah, I see. I'll make this fix and I think this might actually simplify
the code.

just to double check, it's fine for IPNetwork to remain hashable if
set_prefix() actually returned a new object, correct?

> Cheers,
> Nick.
>
> --
> Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia
> ---------------------------------------------------------------
>
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