From 6f81e84fa7ae601d36b560086a1eaf418cc378d7 Mon Sep 17 00:00:00 2001
From: "s.kyon" <251157463+skyon0522-ai@users.noreply.github.com>
Date: Thu, 8 Oct 2026 17:29:12 +0900
Subject: [PATCH 1/3] Preserve astuple filters for dictionary keys and values

---
 changelog.d/astuple-mapping-filter.change.md |  1 +
 src/attr/_funcs.py                           |  4 ++++
 tests/test_funcs.py                          | 23 ++++++++++++++++++++
 3 files changed, 28 insertions(+)
 create mode 100644 changelog.d/astuple-mapping-filter.change.md

diff --git a/changelog.d/astuple-mapping-filter.change.md b/changelog.d/astuple-mapping-filter.change.md
new file mode 100644
index 000000000..7caf59646
--- /dev/null
+++ b/changelog.d/astuple-mapping-filter.change.md
@@ -0,0 +1 @@
+`attrs.astuple()` and `attr.astuple()` now apply the *filter* to attrs instances used as dictionary keys and values, consistently with other recursive conversions.
diff --git a/src/attr/_funcs.py b/src/attr/_funcs.py
index d213efc22..e7f7784b0 100644
--- a/src/attr/_funcs.py
+++ b/src/attr/_funcs.py
@@ -238,6 +238,8 @@ def astuple(
     Return the *attrs* attribute values of *inst* as a tuple.
 
     Optionally recurse into other *attrs*-decorated classes.
+    When recursing, *filter* also applies to *attrs* instances used as dictionary
+    keys and values.
 
     Args:
         inst: Instance of an *attrs*-decorated class.
@@ -322,6 +324,7 @@ def astuple(
                             (
                                 astuple(
                                     kk,
+                                    filter=filter,
                                     tuple_factory=tuple_factory,
                                     retain_collection_types=retain,
                                 )
@@ -331,6 +334,7 @@ def astuple(
                             (
                                 astuple(
                                     vv,
+                                    filter=filter,
                                     tuple_factory=tuple_factory,
                                     retain_collection_types=retain,
                                 )
diff --git a/tests/test_funcs.py b/tests/test_funcs.py
index f35a9a564..9c60dcfab 100644
--- a/tests/test_funcs.py
+++ b/tests/test_funcs.py
@@ -409,6 +409,29 @@ def test_dicts(self, C, tuple_factory):
         assert tuple_factory([1, {"a": tuple_factory([4, 5])}]) == res
         assert isinstance(res, tuple_factory)
 
+    @pytest.mark.parametrize("retain", [False, True])
+    @pytest.mark.parametrize("container", MAPPING_TYPES)
+    def test_dicts_filter(self, C, retain, container):
+        """
+        Filters apply to attrs instances used as dictionary keys and values.
+        """
+
+        @attr.s(frozen=True)
+        class Key:
+            x = attr.ib()
+            y = attr.ib()
+
+        inst = C(container({Key(1, 2): C(3, 4)}), 5)
+
+        result = astuple(
+            inst,
+            filter=lambda a, v: a.name != "y",
+            retain_collection_types=retain,
+        )
+
+        assert ({(1,): (3,)},) == result
+        assert (container if retain else dict) is type(result[0])
+
     @given(container=st.sampled_from(SEQUENCE_TYPES))
     def test_lists_tuples_retain_type(self, container, C):
         """

From 3eb74883d6a04ee3a9198cef3291f86b94f97efc Mon Sep 17 00:00:00 2001
From: "s.kyon" <251157463+skyon0522-ai@users.noreply.github.com>
Date: Thu, 8 Oct 2026 17:44:04 +0900
Subject: [PATCH 2/3] Document mapping filter behavior change

---
 src/attr/_funcs.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/attr/_funcs.py b/src/attr/_funcs.py
index e7f7784b0..ffa7a7a86 100644
--- a/src/attr/_funcs.py
+++ b/src/attr/_funcs.py
@@ -270,6 +270,8 @@ def astuple(
             If *cls* is not an *attrs* class.
 
     ..  versionadded:: 16.2.0
+    ..  versionchanged:: 26.2.0
+        Apply *filter* to attrs instances in dictionary keys and values.
     """
     attrs = fields(inst.__class__)
     rv = []

From 9dbbede1f14c1f60ad155b75a208d53fbce55f98 Mon Sep 17 00:00:00 2001
From: "s.kyon" <251157463+skyon0522-ai@users.noreply.github.com>
Date: Thu, 8 Oct 2026 17:55:26 +0900
Subject: [PATCH 3/3] Name changelog fragment for PR 1641

---
 changelog.d/{astuple-mapping-filter.change.md => 1641.change.md} | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 rename changelog.d/{astuple-mapping-filter.change.md => 1641.change.md} (100%)

diff --git a/changelog.d/astuple-mapping-filter.change.md b/changelog.d/1641.change.md
similarity index 100%
rename from changelog.d/astuple-mapping-filter.change.md
rename to changelog.d/1641.change.md