Support the scope ID in IPv6Interface.exploded too

IPv6Interface.exploded silently omitted the scope ID, unlike str() and
compressed.  Attach it in one place, before the prefix length, so that
all three representations agree.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: serhiy-storchaka

Lib/ipaddress.py

@@ -1911,14 +1911,18 @@ def _explode_shorthand_ip_string(self):
         elif isinstance(self, IPv6Interface):
             ip_str = str(self.ip)
         else:
-            ip_str = str(self._string_from_ip_int(self._ip))
+            ip_str = self._string_from_ip_int(self._ip)
 
         ip_int = self._ip_int_from_string(ip_str)
         hex_str = '%032x' % ip_int
         exploded = ':'.join([hex_str[x:x+4] for x in range(0, 32, 4)])
-        if isinstance(self, (_BaseNetwork, IPv6Interface)):
+        if isinstance(self, _BaseNetwork):
             return '%s/%d' % (exploded, self._prefixlen)
-        return exploded + '%' + self._scope_id if self._scope_id else exploded
+        if self._scope_id:
+            exploded = '%s%%%s' % (exploded, self._scope_id)
+        if isinstance(self, IPv6Interface):
+            return '%s/%d' % (exploded, self._prefixlen)
+        return exploded
 
     def _reverse_pointer(self):
         """Return the reverse DNS pointer name for the IPv6 address.

Lib/test/test_ipaddress.py

@@ -2720,6 +2720,10 @@ def testExplodeShortHandIpStr(self):
                          ipaddress.IPv6Interface('::1/128').exploded)
         self.assertEqual('fe80:0000:0000:0000:0000:0000:0000:0001%1',
                          ipaddress.IPv6Address('fe80::1%1').exploded)
+        self.assertEqual('fe80:0000:0000:0000:0000:0000:0000:0001%eth0',
+                         ipaddress.IPv6Address('fe80::1%eth0').exploded)
+        self.assertEqual('fe80:0000:0000:0000:0000:0000:0000:0001%1/64',
+                         ipaddress.IPv6Interface('fe80::1%1/64').exploded)
         # issue 77
         self.assertEqual('2001:0000:5ef5:79fd:0000:059d:a0e5:0ba1',
                          addr2.exploded)

Misc/NEWS.d/next/Library/2021-06-03-22-23-38.bpo-44012.BK3HfA.rst

@@ -1 +1,5 @@
-:meth:`ipaddress.IPv6Address.exploded` now supports IPv6 addresses with a ``scope_id`` (link-local addresses)
+:attr:`ipaddress.IPv6Address.exploded` and
+:attr:`ipaddress.IPv6Interface.exploded` now support addresses with a scope
+ID (link-local addresses).
+Previously the former raised :exc:`~ipaddress.AddressValueError`
+and the latter omitted the scope ID.