gh-149722: Fix ipaddress.collapse_addresses()

Doc/library/ipaddress.rst

@@ -1007,13 +1007,16 @@ The module also provides the following module level functions:
 
    Return an iterator of the collapsed :class:`IPv4Network` or
    :class:`IPv6Network` objects.  *addresses* is an :term:`iterable` of
-   :class:`IPv4Network` or :class:`IPv6Network` objects.  A :exc:`TypeError` is
-   raised if *addresses* contains mixed version objects.
+   :class:`IPv4Address`, :class:`IPv6Address`, :class:`IPv4Network` or
+   :class:`IPv6Network` objects.
+   A :exc:`TypeError` is raised if *addresses* contains mixed version objects.
 
-   >>> [ipaddr for ipaddr in
-   ... ipaddress.collapse_addresses([ipaddress.IPv4Network('192.0.2.0/25'),
-   ... ipaddress.IPv4Network('192.0.2.128/25')])]
+   >>> list(ipaddress.collapse_addresses([ipaddress.IPv4Network('192.0.2.0/25'),
+   ... ipaddress.IPv4Network('192.0.2.128/25')]))
    [IPv4Network('192.0.2.0/24')]
+   >>> list(ipaddress.collapse_addresses([ipaddress.IPv4Address('192.0.2.0'),
+   ... ipaddress.IPv4Address('192.0.2.1'), ipaddress.IPv4Network('192.0.2.2/31')]))
+   [IPv4Network('192.0.2.0/30')]
 
 
 .. function:: get_mixed_type_key(obj)

Lib/ipaddress.py

@@ -299,21 +299,22 @@ def _collapse_addresses_internal(addresses):
 
 
 def collapse_addresses(addresses):
-    """Collapse a list of IP objects.
+    """Collapse an iterable of IP addresses or networks.
 
     Example:
         collapse_addresses([IPv4Network('192.0.2.0/25'),
                             IPv4Network('192.0.2.128/25')]) ->
                            [IPv4Network('192.0.2.0/24')]
 
     Args:
-        addresses: An iterable of IPv4Network or IPv6Network objects.
+        addresses: An iterable of IPv4Address, IPv6Address, IPv4Network or
+          IPv6Network objects.
 
     Returns:
         An iterator of the collapsed IPv(4|6)Network objects.
 
     Raises:
-        TypeError: If passed a list of mixed version objects.
+        TypeError: If passed an iterable of mixed version objects.
 
     """
     addrs = []
@@ -322,24 +323,19 @@ def collapse_addresses(addresses):
 
     # split IP addresses and networks
     for ip in addresses:
-        if isinstance(ip, _BaseAddress):
-            if ips and ips[-1].version != ip.version:
-                raise TypeError("%s and %s are not of the same version" % (
-                                 ip, ips[-1]))
+        if isinstance(ip, _BaseAddress) and not hasattr(ip, 'ip'):
             ips.append(ip)
-        elif ip._prefixlen == ip.max_prefixlen:
-            if ips and ips[-1].version != ip.version:
-                raise TypeError("%s and %s are not of the same version" % (
-                                 ip, ips[-1]))
-            try:
-                ips.append(ip.ip)
-            except AttributeError:
+        elif isinstance(ip, _BaseNetwork):
+            if ip._prefixlen == ip.max_prefixlen:
                 ips.append(ip.network_address)
+            else:
+                if nets and nets[-1].version != ip.version:
+                    raise TypeError("%s and %s are not of the same version" % (
+                                    ip, nets[-1]))
+                nets.append(ip)
         else:
-            if nets and nets[-1].version != ip.version:
-                raise TypeError("%s and %s are not of the same version" % (
-                                 ip, nets[-1]))
-            nets.append(ip)
+            raise TypeError("expected an iterable of IP addresses or "
+                            "networks, not %s" % type(ip).__name__)
 
     # sort and dedup
     ips = sorted(set(ips))

Lib/test/test_ipaddress.py

@@ -1845,6 +1845,9 @@ def testSlash0Constructor(self):
                           '1.2.3.4/0')
 
     def testCollapsing(self):
+        collapsed = ipaddress.collapse_addresses([])
+        self.assertEqual(list(collapsed), [])
+
         # test only IP addresses including some duplicates
         ip1 = ipaddress.IPv4Address('1.1.1.0')
         ip2 = ipaddress.IPv4Address('1.1.1.1')
@@ -1858,27 +1861,21 @@ def testCollapsing(self):
         self.assertEqual(list(collapsed),
                 [ipaddress.IPv4Network('1.1.1.0/30'),
                  ipaddress.IPv4Network('1.1.1.4/32')])
-
-        # test a mix of IP addresses and networks including some duplicates
-        ip1 = ipaddress.IPv4Address('1.1.1.0')
-        ip2 = ipaddress.IPv4Address('1.1.1.1')
-        ip3 = ipaddress.IPv4Address('1.1.1.2')
-        ip4 = ipaddress.IPv4Address('1.1.1.3')
-        #ip5 = ipaddress.IPv4Interface('1.1.1.4/30')
-        #ip6 = ipaddress.IPv4Interface('1.1.1.4/30')
-        # check that addresses are subsumed properly.
-        collapsed = ipaddress.collapse_addresses([ip1, ip2, ip3, ip4])
+        collapsed = ipaddress.collapse_addresses([ip1])
         self.assertEqual(list(collapsed),
-                         [ipaddress.IPv4Network('1.1.1.0/30')])
+                [ipaddress.IPv4Network('1.1.1.0/32')])
+        # test same IP addresses
+        self.assertEqual(list(ipaddress.collapse_addresses([ip1, ip1, ip6])),
+                [ipaddress.ip_network('1.1.1.0/32')])
 
         # test only IP networks
         ip1 = ipaddress.IPv4Network('1.1.0.0/24')
         ip2 = ipaddress.IPv4Network('1.1.1.0/24')
         ip3 = ipaddress.IPv4Network('1.1.2.0/24')
         ip4 = ipaddress.IPv4Network('1.1.3.0/24')
         ip5 = ipaddress.IPv4Network('1.1.4.0/24')
-        # stored in no particular order b/c we want CollapseAddr to call
-        # [].sort
+        # stored in no particular order b/c we want collapse_addresses()
+        # to call sorted()
         ip6 = ipaddress.IPv4Network('1.1.0.0/22')
         # check that addresses are subsumed properly.
         collapsed = ipaddress.collapse_addresses([ip1, ip2, ip3, ip4, ip5,
@@ -1893,16 +1890,9 @@ def testCollapsing(self):
                          [ipaddress.IPv4Network('1.1.0.0/23')])
 
         # test same IP networks
-        ip_same1 = ip_same2 = ipaddress.IPv4Network('1.1.1.1/32')
-        self.assertEqual(list(ipaddress.collapse_addresses(
-                    [ip_same1, ip_same2])),
-                         [ip_same1])
+        self.assertEqual(list(ipaddress.collapse_addresses([ip1, ip1])),
+                         [ip1])
 
-        # test same IP addresses
-        ip_same1 = ip_same2 = ipaddress.IPv4Address('1.1.1.1')
-        self.assertEqual(list(ipaddress.collapse_addresses(
-                    [ip_same1, ip_same2])),
-                         [ipaddress.ip_network('1.1.1.1/32')])
         ip1 = ipaddress.IPv6Network('2001::/100')
         ip2 = ipaddress.IPv6Network('2001::/120')
         ip3 = ipaddress.IPv6Network('2001::/96')
@@ -1917,6 +1907,21 @@ def testCollapsing(self):
         collapsed = ipaddress.collapse_addresses([ip1, ip2, ip3])
         self.assertEqual(list(collapsed), [ip3])
 
+        # test a mix of IP addresses and networks
+        ip1 = ipaddress.IPv4Address('1.1.1.0')
+        ip2 = ipaddress.IPv4Address('1.1.1.1')
+        ip3 = ipaddress.IPv4Network('1.1.1.2/31')
+        # check that addresses are subsumed properly.
+        collapsed = ipaddress.collapse_addresses([ip1, ip2, ip3])
+        self.assertEqual(list(collapsed),
+                         [ipaddress.IPv4Network('1.1.1.0/30')])
+
+        # unsupported types
+        self.assertRaises(TypeError, ipaddress.collapse_addresses, [42])
+        self.assertRaises(TypeError, ipaddress.collapse_addresses, [None])
+        self.assertRaises(TypeError, ipaddress.collapse_addresses,
+                          [ipaddress.IPv4Interface('1.1.1.4/30')])
+
         # the toejam test
         addr_tuples = [
                 (ipaddress.ip_address('1.1.1.1'),
@@ -1941,6 +1946,24 @@ def testCollapsing(self):
         for ip1, ip2 in addr_tuples:
             self.assertRaises(TypeError, ipaddress.collapse_addresses,
                               [ip1, ip2])
+        for ip1 in [
+            ipaddress.ip_address('1.1.1.1'),
+            ipaddress.IPv4Network('1.1.0.0/24'),
+            ipaddress.IPv4Network('1.1.0.0/32'),
+        ]:
+            for ip2 in [
+                ipaddress.ip_address('::1'),
+                ipaddress.IPv6Network('2001::/120'),
+                ipaddress.IPv6Network('2001::/128'),
+                ipaddress.ip_address('::1%scope'),
+                ipaddress.IPv6Network('2001::%scope/120'),
+                ipaddress.IPv6Network('2001::%scope/128'),
+            ]:
+                with self.subTest(ip1=ip1, ip2=ip2):
+                    with self.assertRaises(TypeError):
+                        list(ipaddress.collapse_addresses([ip1, ip2]))
+                    with self.assertRaises(TypeError):
+                        list(ipaddress.collapse_addresses([ip2, ip1]))
 
     def testSummarizing(self):
         #ip = ipaddress.ip_address

Misc/NEWS.d/next/Library/2026-05-12-14-53-07.gh-issue-149722.L93mk7.rst

@@ -0,0 +1,3 @@
+Make :func:`ipaddress.collapse_addresses` always raising ``TypeError`` for
+unsupported types, including IP interfaces. Document that IP addresses are
+supported.