[3.13] gh-141497: Make ipaddress.IP{v4,v6}Network.hosts() always returning an iterato...

(cherry picked from commit 6b1bdf6c7a6c87f12a247a125e25f8e721cc731e)

Co-authored-by: Krishna Chaitanya <141550576+XChaitanyaX@users.noreply.github.com>

diff --git a/Lib/ipaddress.py b/Lib/ipaddress.py
index 67e45450fc1c9f672d5d5635d50bb4b389bd8075..4235ed877b8586c58d5986d907175d205b845584 100644 (file)
--- a/Lib/ipaddress.py
+++ b/Lib/ipaddress.py
@@ -1559,7 +1559,7 @@ class IPv4Network(_BaseV4, _BaseNetwork):
         if self._prefixlen == (self._max_prefixlen - 1):
             self.hosts = self.__iter__
         elif self._prefixlen == (self._max_prefixlen):
-            self.hosts = lambda: [IPv4Address(addr)]
+            self.hosts = lambda: iter((IPv4Address(addr),))
 
     @property
     @functools.lru_cache()
@@ -2359,7 +2359,7 @@ class IPv6Network(_BaseV6, _BaseNetwork):
         if self._prefixlen == (self._max_prefixlen - 1):
             self.hosts = self.__iter__
         elif self._prefixlen == self._max_prefixlen:
-            self.hosts = lambda: [IPv6Address(addr)]
+            self.hosts = lambda: iter((IPv6Address(addr),))
 
     def hosts(self):
         """Generate Iterator over usable hosts in a network.

diff --git a/Lib/test/test_ipaddress.py b/Lib/test/test_ipaddress.py
index e69e12495ad5c1df3a7adbdfbd3917c8a66501a5..ad7cd573129981409437a5588e219ed029dd805e 100644 (file)
--- a/Lib/test/test_ipaddress.py
+++ b/Lib/test/test_ipaddress.py
@@ -12,6 +12,7 @@ import operator
 import pickle
 import ipaddress
 import weakref
+from collections.abc import Iterator
 from test.support import LARGEST, SMALLEST
 
 
@@ -1472,18 +1473,27 @@ class IpaddrUnitTest(unittest.TestCase):
                          self.ipv6_scoped_network.supernet(new_prefix=62))
 
     def testHosts(self):
+        hosts = self.ipv4_network.hosts()
+        self.assertIsInstance(hosts, Iterator)
+        self.assertEqual(ipaddress.IPv4Address('1.2.3.1'), next(hosts))
         hosts = list(self.ipv4_network.hosts())
         self.assertEqual(254, len(hosts))
         self.assertEqual(ipaddress.IPv4Address('1.2.3.1'), hosts[0])
         self.assertEqual(ipaddress.IPv4Address('1.2.3.254'), hosts[-1])
 
         ipv6_network = ipaddress.IPv6Network('2001:658:22a:cafe::/120')
+        hosts = ipv6_network.hosts()
+        self.assertIsInstance(hosts, Iterator)
+        self.assertEqual(ipaddress.IPv6Address('2001:658:22a:cafe::1'), next(hosts))
         hosts = list(ipv6_network.hosts())
         self.assertEqual(255, len(hosts))
         self.assertEqual(ipaddress.IPv6Address('2001:658:22a:cafe::1'), hosts[0])
         self.assertEqual(ipaddress.IPv6Address('2001:658:22a:cafe::ff'), hosts[-1])
 
         ipv6_scoped_network = ipaddress.IPv6Network('2001:658:22a:cafe::%scope/120')
+        hosts = ipv6_scoped_network.hosts()
+        self.assertIsInstance(hosts, Iterator)
+        self.assertEqual((ipaddress.IPv6Address('2001:658:22a:cafe::1')), next(hosts))
         hosts = list(ipv6_scoped_network.hosts())
         self.assertEqual(255, len(hosts))
         self.assertEqual(ipaddress.IPv6Address('2001:658:22a:cafe::1'), hosts[0])
@@ -1494,6 +1504,12 @@ class IpaddrUnitTest(unittest.TestCase):
                  ipaddress.IPv4Address('2.0.0.1')]
         str_args = '2.0.0.0/31'
         tpl_args = ('2.0.0.0', 31)
+        hosts = ipaddress.ip_network(str_args).hosts()
+        self.assertIsInstance(hosts, Iterator)
+        self.assertEqual(next(hosts), addrs[0])
+        hosts = ipaddress.ip_network(tpl_args).hosts()
+        self.assertIsInstance(hosts, Iterator)
+        self.assertEqual(next(hosts), addrs[0])
         self.assertEqual(addrs, list(ipaddress.ip_network(str_args).hosts()))
         self.assertEqual(addrs, list(ipaddress.ip_network(tpl_args).hosts()))
         self.assertEqual(list(ipaddress.ip_network(str_args).hosts()),
@@ -1503,6 +1519,12 @@ class IpaddrUnitTest(unittest.TestCase):
         addrs = [ipaddress.IPv4Address('1.2.3.4')]
         str_args = '1.2.3.4/32'
         tpl_args = ('1.2.3.4', 32)
+        hosts = ipaddress.ip_network(str_args).hosts()
+        self.assertIsInstance(hosts, Iterator)
+        self.assertEqual(next(hosts), addrs[0])
+        hosts = ipaddress.ip_network(tpl_args).hosts()
+        self.assertIsInstance(hosts, Iterator)
+        self.assertEqual(next(hosts), addrs[0])
         self.assertEqual(addrs, list(ipaddress.ip_network(str_args).hosts()))
         self.assertEqual(addrs, list(ipaddress.ip_network(tpl_args).hosts()))
         self.assertEqual(list(ipaddress.ip_network(str_args).hosts()),
@@ -1512,6 +1534,12 @@ class IpaddrUnitTest(unittest.TestCase):
                  ipaddress.IPv6Address('2001:658:22a:cafe::1')]
         str_args = '2001:658:22a:cafe::/127'
         tpl_args = ('2001:658:22a:cafe::', 127)
+        hosts = ipaddress.ip_network(str_args).hosts()
+        self.assertIsInstance(hosts, Iterator)
+        self.assertEqual(next(hosts), addrs[0])
+        hosts = ipaddress.ip_network(tpl_args).hosts()
+        self.assertIsInstance(hosts, Iterator)
+        self.assertEqual(next(hosts), addrs[0])
         self.assertEqual(addrs, list(ipaddress.ip_network(str_args).hosts()))
         self.assertEqual(addrs, list(ipaddress.ip_network(tpl_args).hosts()))
         self.assertEqual(list(ipaddress.ip_network(str_args).hosts()),
@@ -1520,6 +1548,12 @@ class IpaddrUnitTest(unittest.TestCase):
         addrs = [ipaddress.IPv6Address('2001:658:22a:cafe::1'), ]
         str_args = '2001:658:22a:cafe::1/128'
         tpl_args = ('2001:658:22a:cafe::1', 128)
+        hosts = ipaddress.ip_network(str_args).hosts()
+        self.assertIsInstance(hosts, Iterator)
+        self.assertEqual(next(hosts), addrs[0])
+        hosts = ipaddress.ip_network(tpl_args).hosts()
+        self.assertIsInstance(hosts, Iterator)
+        self.assertEqual(next(hosts), addrs[0])
         self.assertEqual(addrs, list(ipaddress.ip_network(str_args).hosts()))
         self.assertEqual(addrs, list(ipaddress.ip_network(tpl_args).hosts()))
         self.assertEqual(list(ipaddress.ip_network(str_args).hosts()),

diff --git a/Misc/NEWS.d/next/Library/2025-11-14-16-24-20.gh-issue-141497.L_CxDJ.rst b/Misc/NEWS.d/next/Library/2025-11-14-16-24-20.gh-issue-141497.L_CxDJ.rst
new file mode 100644 (file)
index 0000000..328bfe0
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-11-14-16-24-20.gh-issue-141497.L_CxDJ.rst
@@ -0,0 +1,4 @@
+:mod:`ipaddress`: ensure that the methods
+:meth:`IPv4Network.hosts() <ipaddress.IPv4Network.hosts>` and
+:meth:`IPv6Network.hosts() <ipaddress.IPv6Network.hosts>` always return an
+iterator.