From 42df0239568076e80961663248fe2a5852d4b656 Mon Sep 17 00:00:00 2001
From: decorator-factory <42166884+decorator-factory@users.noreply.github.com>
Date: Wed, 1 Oct 2025 23:33:33 +0000
Subject: [PATCH 1/4] Make `copy.replace` more strongly typed

---
 stdlib/copy.pyi | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/stdlib/copy.pyi b/stdlib/copy.pyi
index 373899ea2635..3c4cb07f43f1 100644
--- a/stdlib/copy.pyi
+++ b/stdlib/copy.pyi
@@ -1,15 +1,17 @@
 import sys
 from typing import Any, Protocol, TypeVar, type_check_only
+from typing_extensions import ParamSpec
 
 __all__ = ["Error", "copy", "deepcopy"]
 
 _T = TypeVar("_T")
 _RT_co = TypeVar("_RT_co", covariant=True)
+_P = ParamSpec("_P")
 
 @type_check_only
-class _SupportsReplace(Protocol[_RT_co]):
+class _SupportsReplace(Protocol[_P, _RT_co]):
     # In reality doesn't support args, but there's no great way to express this.
-    def __replace__(self, /, *_: Any, **changes: Any) -> _RT_co: ...
+    def __replace__(self, /, *_: _P.args, **changes: _P.kwargs) -> _RT_co: ...
 
 # None in CPython but non-None in Jython
 PyStringMap: Any
@@ -20,8 +22,12 @@ def copy(x: _T) -> _T: ...
 
 if sys.version_info >= (3, 13):
     __all__ += ["replace"]
-    # The types accepted by `**changes` match those of `obj.__replace__`.
-    def replace(obj: _SupportsReplace[_RT_co], /, **changes: Any) -> _RT_co: ...
+
+    def replace(
+        obj: _SupportsReplace[_P, _RT_co], /,
+        *_: _P.args,  # does not accept positional arguments at runtime
+        **changes: _P.kwargs,
+    ) -> _RT_co: ...
 
 class Error(Exception): ...
 

From 51685bf21a0555cd16a70b55d8764ef08844cdd1 Mon Sep 17 00:00:00 2001
From: decorator-factory <42166884+decorator-factory@users.noreply.github.com>
Date: Wed, 1 Oct 2025 23:51:02 +0000
Subject: [PATCH 2/4] Format code with black

---
 stdlib/copy.pyi | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/stdlib/copy.pyi b/stdlib/copy.pyi
index 3c4cb07f43f1..aec0d031f8b6 100644
--- a/stdlib/copy.pyi
+++ b/stdlib/copy.pyi
@@ -24,9 +24,7 @@ if sys.version_info >= (3, 13):
     __all__ += ["replace"]
 
     def replace(
-        obj: _SupportsReplace[_P, _RT_co], /,
-        *_: _P.args,  # does not accept positional arguments at runtime
-        **changes: _P.kwargs,
+        obj: _SupportsReplace[_P, _RT_co], /, *_: _P.args, **changes: _P.kwargs  # does not accept positional arguments at runtime
     ) -> _RT_co: ...
 
 class Error(Exception): ...

From 9d38af38d9925dbdc73834ccaacf374ae525e73f Mon Sep 17 00:00:00 2001
From: decorator-factory <42166884+decorator-factory@users.noreply.github.com>
Date: Wed, 1 Oct 2025 23:54:22 +0000
Subject: [PATCH 3/4] Fix stdlib test for `copy.replace`

---
 stdlib/@tests/test_cases/check_copy.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/stdlib/@tests/test_cases/check_copy.py b/stdlib/@tests/test_cases/check_copy.py
index c9d4fa877e91..59896851d737 100644
--- a/stdlib/@tests/test_cases/check_copy.py
+++ b/stdlib/@tests/test_cases/check_copy.py
@@ -10,7 +10,7 @@ class ReplaceableClass:
     def __init__(self, val: int) -> None:
         self.val = val
 
-    def __replace__(self, val: int) -> Self:
+    def __replace__(self, /, *, val: int) -> Self:
         cpy = copy.copy(self)
         cpy.val = val
         return cpy
@@ -29,11 +29,11 @@ class Box(Generic[_T_co]):
     def __init__(self, value: _T_co, /) -> None:
         self.value = value
 
-    def __replace__(self, value: str) -> Box[str]:
+    def __replace__(self, /, *, value: str) -> Box[str]:
         return Box(value)
 
 
 if sys.version_info >= (3, 13):
     box1: Box[int] = Box(42)
-    box2 = copy.replace(box1, val="spam")
+    box2 = copy.replace(box1, value="spam")
     assert_type(box2, Box[str])

From b7b15d4bf48c49143d1455a98ef8cc64339c0bbf Mon Sep 17 00:00:00 2001
From: decorator-factory <42166884+decorator-factory@users.noreply.github.com>
Date: Thu, 2 Oct 2025 00:01:53 +0000
Subject: [PATCH 4/4] Add exemption for copy.replace not matching runtime
 signature

---
 stdlib/@tests/stubtest_allowlists/py313.txt | 3 +++
 stdlib/@tests/stubtest_allowlists/py314.txt | 2 ++
 2 files changed, 5 insertions(+)

diff --git a/stdlib/@tests/stubtest_allowlists/py313.txt b/stdlib/@tests/stubtest_allowlists/py313.txt
index 12553bf684ee..f3df7cc2248c 100644
--- a/stdlib/@tests/stubtest_allowlists/py313.txt
+++ b/stdlib/@tests/stubtest_allowlists/py313.txt
@@ -2,6 +2,9 @@
 # New errors in Python 3.13
 # =========================
 
+# No way to express keyword-only ParamSpec
+copy.replace
+
 
 # ====================================
 # Pre-existing errors from Python 3.12
diff --git a/stdlib/@tests/stubtest_allowlists/py314.txt b/stdlib/@tests/stubtest_allowlists/py314.txt
index 0fcdcbb84d97..98045f819fd2 100644
--- a/stdlib/@tests/stubtest_allowlists/py314.txt
+++ b/stdlib/@tests/stubtest_allowlists/py314.txt
@@ -45,6 +45,8 @@ importlib.util.Loader.exec_module  # See Lib/importlib/_abc.py. Might be defined
 # Pre-existing errors from Python 3.13
 # ====================================
 
+# No way to express keyword-only ParamSpec
+copy.replace
 
 # =======
 # >= 3.12