gh-141647: fix IP address/network comparison methods

[picnixz]

I think this patch should cover the cases. I'm unsure whether this will break more stuff or not but I do know that using < and __lt__ return different boolean results which can break many things.

@serhiy-storchaka I really want a second eye here so PTAL whenever you've got time. TiA!

• Issue: Use of .version attribute in ipaddress classes break many methods #141647

[serhiy-storchaka]

Please make benchmarks for equality and order comparison.

[serhiy-storchaka]

Would not moving this code to a function add an overhead for fast operators?

[picnixz]

I will check how much overhead I'm getting.

[yihong0618]

why the benchmark is faster its interesting...

[picnixz]

It's likely noise. Benchmarks weren't run on an idle system.

[yihong0618]

It's likely noise. Benchmarks weren't run on an idle system.

thank you~

[picnixz]

So I'm a bit surprised but here are the numbers:

+---------------------------------------------+---------------+-----------------------+
| Benchmark                                   | ipaddress-ref | ipaddress-new         |
+=============================================+===============+=======================+
| address.__eq__[1.2.3.4,5.6.7.8]             | 39.7 ns       | 41.0 ns: 1.03x slower |
+---------------------------------------------+---------------+-----------------------+
| interface.__eq__[192.0.2.0/32,192.0.2.0/32] | 242 ns        | 264 ns: 1.09x slower  |
+---------------------------------------------+---------------+-----------------------+
| interface.__lt__[192.0.2.0/32,192.0.8.0/32] | 344 ns        | 317 ns: 1.09x faster  |
+---------------------------------------------+---------------+-----------------------+
| interface.__eq__[192.0.2.0/32,192.0.2.0/24] | 253 ns        | 245 ns: 1.03x faster  |
+---------------------------------------------+---------------+-----------------------+
| interface.__lt__[192.0.8.0/32,192.0.8.0/32] | 389 ns        | 362 ns: 1.07x faster  |
+---------------------------------------------+---------------+-----------------------+
| network.__lt__[192.0.2.0/32,192.0.8.0/32]   | 160 ns        | 167 ns: 1.04x slower  |
+---------------------------------------------+---------------+-----------------------+
| network.__eq__[192.0.8.0/32,192.0.2.0/24]   | 80.4 ns       | 76.4 ns: 1.05x faster |
+---------------------------------------------+---------------+-----------------------+
| network.__eq__[192.0.2.0/24,192.0.2.0/24]   | 140 ns        | 134 ns: 1.05x faster  |
+---------------------------------------------+---------------+-----------------------+
| network.__lt__[192.0.2.0/24,192.0.2.0/24]   | 173 ns        | 166 ns: 1.04x faster  |
+---------------------------------------------+---------------+-----------------------+
| mixed.__lt__[5.6.7.8,1.2.3.4/32]            | 416 ns        | 387 ns: 1.07x faster  |
+---------------------------------------------+---------------+-----------------------+
| mixed.__lt__[5.6.7.8/32,5.6.7.8/32]         | 372 ns        | 398 ns: 1.07x slower  |
+---------------------------------------------+---------------+-----------------------+
| Geometric mean                              | (ref)         | 1.00x faster          |
+---------------------------------------------+---------------+-----------------------+

This benchmark uses the _check_ip_version additional call and Python 3.14 from uv (since the changes are only in pure Python, it's fine to switch branches). I've also tried those "slower" cases but it's really within the real of noise IMO.

Benchmark script

import ipaddress
import itertools
import operator

import pyperf

seen = set()

def bench_eq(runner, label, x, y, seen):
    name = f"{label}.__eq__[{x},{y}]"
    if name not in seen:
        runner.bench_func(name, operator.__eq__, x, y)
        seen.add(name)

def bench_lt(runner, label, x, y, seen):
    name = f"{label}.__lt__[{x},{y}]"
    if name not in seen:
        runner.bench_func(name, operator.__lt__, x, y)
        seen.add(name)


if __name__ == "__main__":
    runner = pyperf.Runner()
    args = runner.parse_args()
    seen = set()

    for x, y in itertools.combinations_with_replacement(
        [
            ipaddress.IPv4Address("1.2.3.4"),
            ipaddress.IPv4Address("5.6.7.8"),
        ], 2
    ):
        bench_eq(runner, "address", x, y, seen)
        bench_lt(runner, "address", x, y, seen)

    for x, y in itertools.combinations_with_replacement(
        [
            ipaddress.IPv4Interface("192.0.2.0"),
            ipaddress.IPv4Interface("192.0.8.0"),
            ipaddress.IPv4Interface("192.0.2.0/24"),
            ipaddress.IPv4Interface("192.0.8.0/32"),
        ], 2
    ):
        bench_eq(runner, "interface", x, y, seen)
        bench_lt(runner, "interface", x, y, seen)

    for x, y in itertools.combinations_with_replacement(
        [
            ipaddress.IPv4Network("192.0.2.0"),
            ipaddress.IPv4Network("192.0.8.0"),
            ipaddress.IPv4Network("192.0.2.0/24"),
            ipaddress.IPv4Network("192.0.8.0/32"),
        ], 2
    ):
        bench_eq(runner, "network", x, y, seen)
        bench_lt(runner, "network", x, y, seen)

    for x, y in itertools.combinations_with_replacement(
        [
            ipaddress.IPv4Address("1.2.3.4"),
            ipaddress.IPv4Address("5.6.7.8"),
            ipaddress.IPv4Interface("1.2.3.4"),
            ipaddress.IPv4Interface("5.6.7.8"),
            ipaddress.IPv4Interface("1.2.3.4/24"),
            ipaddress.IPv4Interface("5.6.7.8/32"),
        ], 2
    ):
        bench_lt(runner, "mixed", x, y, seen)