[issue3959] Add Google's ipaddr.py to the stdlib

[Clay McClure]

Clay McClure <clay at daemons.net> added the comment:

On Mon, Jun 1, 2009 at 5:02 PM, R. David Murray <report at bugs.python.org> wrote:

>> >>> ipaddr.IPv4('192.168.1.1') == ipaddr.IPv4('192.168.1.1/32')
>> True
>
> As a network engineer I don't see any inherent problem with that equality.
> In fact I make use of that conceptual equality on a regular basis.

For an example of why 192.168.1.1 != 192.168.1.1/32, look no further
than ifconfig:

# ifconfig en0 192.168.1.1/32
# ifconfig en0
en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
	inet 192.168.1.1 netmask 0xffffffff broadcast 192.168.1.1
        ...

# ifconfig en0 192.168.1.1
# ifconfig en0
en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
	inet 192.168.1.1 netmask 0xffffff00 broadcast 192.168.1.255
        ...

Can you provide an example of when 192.168.1.1 does in fact equal
192.168.1.1/32?

> Further, if you were to add a specifically 'address-without-netmask'
> type, the above equality would still be true, because then the above
> would be comparing two addresses-with-netmasks and you would want to
> apply the hostmask to a bare address for convenience.  To get inequality,
> you'd be comparing two different object types...which comparison would
> be False by default.

I don't follow. Assuming hypothetical Address and Network classes, as
accurately models the problem domain, we would have:

False

That seems to me the correct behavior, since an address is in fact not
the same thing as a network.

Clay

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue3959>
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