From 1430948d6c488e99740298ce02c7d60f6eda82c4 Mon Sep 17 00:00:00 2001
From: Seungki Kim <ksg980614@gmail.com>
Date: Mon, 17 Aug 2026 12:11:34 +0900
Subject: [PATCH 1/2] gh-150942: Optimize stringlib split/splitlines with
 _PyList_AppendTakeRef

---
 ...026-08-17-14-00-00.gh-issue-150942.sTrSpL.rst |  4 ++++
 Objects/stringlib/split.h                        | 16 +++++-----------
 2 files changed, 9 insertions(+), 11 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Core_and_Builtins/2026-08-17-14-00-00.gh-issue-150942.sTrSpL.rst

diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-08-17-14-00-00.gh-issue-150942.sTrSpL.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-08-17-14-00-00.gh-issue-150942.sTrSpL.rst
new file mode 100644
index 000000000000000..0623a7736690e57
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2026-08-17-14-00-00.gh-issue-150942.sTrSpL.rst
@@ -0,0 +1,4 @@
+Speed up :meth:`str.split`, :meth:`str.rsplit` and :meth:`str.splitlines`
+(and the corresponding :class:`bytes` and :class:`bytearray` methods) by
+appending result items to the output list without an extra reference-count
+round-trip.
diff --git a/Objects/stringlib/split.h b/Objects/stringlib/split.h
index 0c11b7214e9b0b8..0b23b6430c8d636 100644
--- a/Objects/stringlib/split.h
+++ b/Objects/stringlib/split.h
@@ -4,6 +4,8 @@
 #error must include "stringlib/fastsearch.h" before including this module
 #endif
 
+#include "pycore_list.h"          // _PyList_AppendTakeRef()
+
 /* Overallocate the initial list to reduce the number of reallocs for small
    split sizes.  Eg, "A A A A A A A A A A".split() (10 elements) has three
    resizes, to sizes 4, 8, then 16.  Most observed string splits are for human
@@ -22,12 +24,8 @@
                         (right) - (left));      \
     if (sub == NULL)                            \
         goto onError;                           \
-    if (PyList_Append(list, sub)) {             \
-        Py_DECREF(sub);                         \
-        goto onError;                           \
-    }                                           \
-    else                                        \
-        Py_DECREF(sub);
+    if (_PyList_AppendTakeRef((PyListObject *)list, sub)) \
+        goto onError;
 
 #define SPLIT_ADD(data, left, right) {          \
     sub = STRINGLIB_NEW((data) + (left),        \
@@ -37,12 +35,8 @@
     if (count < MAX_PREALLOC) {                 \
         PyList_SET_ITEM(list, count, sub);      \
     } else {                                    \
-        if (PyList_Append(list, sub)) {         \
-            Py_DECREF(sub);                     \
+        if (_PyList_AppendTakeRef((PyListObject *)list, sub)) \
             goto onError;                       \
-        }                                       \
-        else                                    \
-            Py_DECREF(sub);                     \
     }                                           \
     count++; }
 

From f3fd338f20907014e57588703af9fffd0dee7408 Mon Sep 17 00:00:00 2001
From: Donghee Na <donghee.na92@gmail.com>
Date: Mon, 17 Aug 2026 12:32:24 +0900
Subject: [PATCH 2/2] Delete
 Misc/NEWS.d/next/Core_and_Builtins/2026-08-17-14-00-00.gh-issue-150942.sTrSpL.rst

---
 .../2026-08-17-14-00-00.gh-issue-150942.sTrSpL.rst            | 4 ----
 1 file changed, 4 deletions(-)
 delete mode 100644 Misc/NEWS.d/next/Core_and_Builtins/2026-08-17-14-00-00.gh-issue-150942.sTrSpL.rst

diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-08-17-14-00-00.gh-issue-150942.sTrSpL.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-08-17-14-00-00.gh-issue-150942.sTrSpL.rst
deleted file mode 100644
index 0623a7736690e57..000000000000000
--- a/Misc/NEWS.d/next/Core_and_Builtins/2026-08-17-14-00-00.gh-issue-150942.sTrSpL.rst
+++ /dev/null
@@ -1,4 +0,0 @@
-Speed up :meth:`str.split`, :meth:`str.rsplit` and :meth:`str.splitlines`
-(and the corresponding :class:`bytes` and :class:`bytearray` methods) by
-appending result items to the output list without an extra reference-count
-round-trip.