tj-python · pull · Jan 6, 2026 · Jan 6, 2026 · Jan 6, 2026 · Jan 6, 2026
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
@@ -691,7 +691,6 @@ jobs:
     - build-ubuntu
     - build-ubuntu-ssltests-awslc
     - build-ubuntu-ssltests-openssl
-    - build-android
     - build-ios
     - build-wasi
     - test-hypothesis
@@ -706,6 +705,7 @@ jobs:
       uses: re-actors/alls-green@05ac9388f0aebcb5727afa17fcccfecd6f8ec5fe
       with:
         allowed-failures: >-
+          build-android,
           build-windows-msi,
           build-ubuntu-ssltests-awslc,
           build-ubuntu-ssltests-openssl,

diff --git a/Doc/deprecations/index.rst b/Doc/deprecations/index.rst
@@ -7,6 +7,8 @@ Deprecations
 
 .. include:: pending-removal-in-3.17.rst
 
+.. include:: pending-removal-in-3.18.rst
+
 .. include:: pending-removal-in-3.19.rst
 
 .. include:: pending-removal-in-3.20.rst

diff --git a/Doc/deprecations/pending-removal-in-3.18.rst b/Doc/deprecations/pending-removal-in-3.18.rst
@@ -0,0 +1,9 @@
+Pending removal in Python 3.18
+------------------------------
+
+* :mod:`decimal`:
+
+  * The non-standard and undocumented :class:`~decimal.Decimal` format
+    specifier ``'N'``, which is only supported in the :mod:`!decimal` module's
+    C implementation, has been deprecated since Python 3.13.
+    (Contributed by Serhiy Storchaka in :gh:`89902`.)
diff --git a/Doc/library/os.rst b/Doc/library/os.rst
@@ -1556,6 +1556,15 @@ or `the MSDN <https://msdn.microsoft.com/en-us/library/z0kc8e3z.aspx>`_ on Windo
    .. versionadded:: 3.15
 
 
+.. data:: RWF_ATOMIC
+
+   Write data atomically. Requires alignment to the device's atomic write unit.
+
+   .. availability:: Linux >= 6.11
+
+   .. versionadded:: next
+
+
 .. function:: ptsname(fd, /)
 
    Return the name of the slave pseudo-terminal device associated with the
@@ -1598,6 +1607,7 @@ or `the MSDN <https://msdn.microsoft.com/en-us/library/z0kc8e3z.aspx>`_ on Windo
    - :data:`RWF_SYNC`
    - :data:`RWF_APPEND`
    - :data:`RWF_DONTCACHE`
+   - :data:`RWF_ATOMIC`
 
    Return the total number of bytes actually written.
 
@@ -1969,7 +1979,8 @@ can be inherited by child processes.  Since Python 3.4, file descriptors
 created by Python are non-inheritable by default.
 
 On UNIX, non-inheritable file descriptors are closed in child processes at the
-execution of a new program, other file descriptors are inherited.
+execution of a new program, other file descriptors are inherited. Note that
+non-inheritable file descriptors are still *inherited* by child processes on :func:`os.fork`.
 
 On Windows, non-inheritable handles and file descriptors are closed in child
 processes, except for standard streams (file descriptors 0, 1 and 2: stdin, stdout

diff --git a/Doc/library/stdtypes.rst b/Doc/library/stdtypes.rst
@@ -2190,6 +2190,15 @@ expression support in the :mod:`re` module).
    Nonprintable characters are those in group Separator or Other (Z or C),
    except the ASCII space.
 
+   For example:
+
+   .. doctest::
+
+      >>> ''.isprintable(), ' '.isprintable()
+      (True, True)
+      >>> '\t'.isprintable(), '\n'.isprintable()
+      (False, False)
+
 
 .. method:: str.isspace()
 

diff --git a/Doc/library/tempfile.rst b/Doc/library/tempfile.rst
@@ -225,8 +225,9 @@ The module defines the following user-callable items:
    properly implements the :const:`os.O_EXCL` flag for :func:`os.open`.  The
    file is readable and writable only by the creating user ID.  If the
    platform uses permission bits to indicate whether a file is executable,
-   the file is executable by no one.  The file descriptor is not inherited
-   by child processes.
+   the file is executable by no one.
+
+   The file descriptor is :ref:`not inherited by child processes <fd_inheritance>`.
 
    Unlike :func:`TemporaryFile`, the user of :func:`mkstemp` is responsible
    for deleting the temporary file when done with it.

diff --git a/Doc/whatsnew/3.13.rst b/Doc/whatsnew/3.13.rst
@@ -1861,6 +1861,7 @@ New Deprecations
   * Deprecate the non-standard and undocumented :class:`~decimal.Decimal`
     format specifier ``'N'``,
     which is only supported in the :mod:`!decimal` module's C implementation.
+    Scheduled to be removed in Python 3.18.
     (Contributed by Serhiy Storchaka in :gh:`89902`.)
 
 * :mod:`dis`:
@@ -2024,6 +2025,8 @@ New Deprecations
 
 .. include:: ../deprecations/pending-removal-in-3.17.rst
 
+.. include:: ../deprecations/pending-removal-in-3.18.rst
+
 .. include:: ../deprecations/pending-removal-in-3.19.rst
 
 .. include:: ../deprecations/pending-removal-in-3.20.rst

diff --git a/Doc/whatsnew/3.14.rst b/Doc/whatsnew/3.14.rst
@@ -2718,6 +2718,8 @@ New deprecations
 
 .. include:: ../deprecations/pending-removal-in-3.17.rst
 
+.. include:: ../deprecations/pending-removal-in-3.18.rst
+
 .. include:: ../deprecations/pending-removal-in-3.19.rst
 
 .. include:: ../deprecations/pending-removal-in-3.20.rst

diff --git a/Doc/whatsnew/3.15.rst b/Doc/whatsnew/3.15.rst
@@ -891,7 +891,11 @@ Results from the `pyperformance <https://github.com/python/pyperformance>`__
 benchmark suite report
 `3-4% <https://github.com/facebookexperimental/free-threading-benchmarking/blob/main/results/bm-20251214-3.15.0a2%2B-6cddf04-JIT/bm-20251214-vultr-x86_64-python-6cddf04344a1e8ca9df5-3.15.0a2%2B-6cddf04-vs-base.svg>`__
 geometric mean performance improvement for the JIT over the standard CPython
-interpreter built with all optimizations enabled. The speedups for JIT
+interpreter built with all optimizations enabled on x86-64 Linux. On AArch64
+macOS, the JIT has a
+`7-8% <https://raw.githubusercontent.com/facebookexperimental/free-threading-benchmarking/refs/heads/main/results/bm-20260103-3.15.0a3%2B-9609574-JIT/bm-20260103-macm4pro-arm64-python-9609574e7fd36edfaa8b-3.15.0a3%2B-9609574-vs-base.svg>`__
+speedup over the :ref:`tail calling interpreter <whatsnew314-tail-call-interpreter>`
+with all optimizations enabled. The speedups for JIT
 builds versus no JIT builds range from roughly 20% slowdown to over
 100% speedup (ignoring the ``unpack_sequence`` microbenchmark) on
 x86-64 Linux and AArch64 macOS systems.
@@ -1171,6 +1175,8 @@ New deprecations
 
 .. include:: ../deprecations/pending-removal-in-3.17.rst
 
+.. include:: ../deprecations/pending-removal-in-3.18.rst
+
 .. include:: ../deprecations/pending-removal-in-3.19.rst
 
 .. include:: ../deprecations/pending-removal-in-3.20.rst

diff --git a/Include/internal/pycore_opcode_metadata.h b/Include/internal/pycore_opcode_metadata.h
diff --git a/Include/internal/pycore_tstate.h b/Include/internal/pycore_tstate.h
@@ -47,10 +47,15 @@ typedef struct _PyJitTracerPreviousState {
     _PyBloomFilter dependencies;
 } _PyJitTracerPreviousState;
 
+typedef struct _PyJitTracerTranslatorState {
+    int jump_backward_seen;
+} _PyJitTracerTranslatorState;
+
 typedef struct _PyJitTracerState {
     _PyUOpInstruction *code_buffer;
     _PyJitTracerInitialState initial_state;
     _PyJitTracerPreviousState prev_state;
+    _PyJitTracerTranslatorState translator_state;
 } _PyJitTracerState;
 
 #endif