GH-151914: Copyedit "What's new in Python 3.16"

Doc/whatsnew/3.16.rst

@@ -62,11 +62,48 @@ Summary -- Release highlights
 .. This section singles out the most important changes in Python 3.16.
    Brevity is key.
 
+* :ref:`Set operations and Unicode properties in regular expressions
+  <whatsnew316-re-set-operations-and-unicode-properties>`.
+* :ref:`Encrypted Client Hello support in ssl <whatsnew316-ssl-ech>`.
+* :ref:`Faster interpreter startup <whatsnew316-interpreter-startup>`.
+* :ref:`Faster UUID generation <whatsnew316-uuid-optimizations>`, with
+  UUIDv4 and UUIDv7 about 15 and 30 times faster in microbenchmarks.
+* :ref:`Build support for tvOS, watchOS, and visionOS
+  <whatsnew316-apple-platforms>`.
+* :ref:`Improved error messages <whatsnew316-improved-error-messages>`.
 
 
 New features
 ============
 
+.. _whatsnew316-improved-error-messages:
+
+Improved error messages
+-----------------------
+
+* :exc:`SyntaxError` messages now suggest Python alternatives to some
+  keywords from other programming languages. For example, ``switch x:``
+  suggests ``match``, ``delete x`` suggests ``del``, and ``function f():``
+  suggests ``def``.
+  (Contributed by Zang Langyan in :gh:`151128`.)
+
+* Improve :exc:`SyntaxError` message for ``&&`` and ``||`` operators,
+  suggesting ``and``/``&`` and ``or``/``|`` respectively.
+  (Contributed by Aniket, Sergey B Kirpichev, and Nikita Sobolev in
+  :gh:`146495`.)
+
+* Suggest the closest valid feature name in the :exc:`SyntaxError` message
+  when an unknown name is imported from :mod:`__future__`.
+  (Contributed by Nikita Sobolev and Pablo Galindo Salgado in :gh:`145868`.)
+
+* :exc:`TypeError` messages for some instance methods called with too many
+  positional arguments now suggest checking whether the method definition is
+  missing the ``self`` parameter. (Contributed by Suren Nihalani in
+  :gh:`152315`.)
+
+* Add context notes to :exc:`TypeError` raised while hashing a
+  :class:`tuple`, identifying the index of the item whose hash failed.
+  (Contributed by Ivan Zorin in :gh:`161433`.)
 
 
 Other language changes
@@ -95,11 +132,6 @@ Other language changes
   they reference) alive indefinitely.
   (Contributed by Łukasz Langa in :gh:`102960`.)
 
-* :exc:`TypeError` messages for some instance methods called with too many
-  positional arguments now suggest checking whether the method definition is
-  missing the ``self`` parameter. (Contributed by Suren Nihalani in
-  :gh:`152315`.)
-
 * :func:`anext` and :func:`aiter` are now implemented in Python instead
   of C.  The awaitable returned by ``anext(it, default)`` and the
   ``__anext__()`` of the iterator returned by ``aiter(callable, ...)`` are
@@ -204,6 +236,19 @@ concurrent.interpreters
   :meth:`~concurrent.interpreters.Interpreter.close`.
   (Contributed by Peter Bierma in :gh:`158370`.)
 
+
+copy
+----
+
+* :func:`copy.replace` now supports :class:`argparse.Namespace`,
+  :class:`optparse.Values`, :class:`decimal.Context`,
+  :class:`tarfile.TarInfo`, and CSV dialects (instances of
+  :class:`csv.Dialect` subclasses and objects returned by
+  :func:`csv.get_dialect`).
+  (Contributed by Serhiy Storchaka and Stan Ulbrych in :gh:`155043`,
+  :gh:`155044`, :gh:`155041`, :gh:`155040`, and :gh:`155033`.)
+
+
 csv
 ---
 
@@ -639,6 +684,8 @@ quopri
 re
 --
 
+.. _whatsnew316-re-set-operations-and-unicode-properties:
+
 * :mod:`re` now supports set operations and nested sets in character classes,
   as described in `Unicode Technical Standard #18
   <https://unicode.org/reports/tr18/>`__: set difference (``[A--B]``),
@@ -709,6 +756,8 @@ sqlite3
 ssl
 ---
 
+.. _whatsnew316-ssl-ech:
+
 * Added support for :ref:`Encrypted Client Hello <ssl-encrypted-client-hello>`
   (ECH) with OpenSSL 4.0 or later. Clients can supply an ECHConfigList
   discovered through DNS, for example using a third-party library such as
@@ -1009,6 +1058,35 @@ zlib
 Optimizations
 =============
 
+.. _whatsnew316-interpreter-startup:
+
+* Interpreter startup is faster, and several common operations have been
+  optimized. Improvements include less work during garbage collection and
+  faster construction of :class:`list`, :class:`dict`, :class:`bytes`, and
+  :class:`bytearray` objects.
+  Startup performance is tracked on the `Python Speed Center
+  <https://speed.python.org/timeline/?exe=12&base=&ben=python_startup.legacy&env=1%2C7&revs=50&equid=off&quarts=on&extr=on>`__.
+  (Contributed by Pablo Galindo Salgado, Cody Maloney, and Pieter Eendebak in
+  :gh:`159137`, :gh:`160858`, :gh:`160913`, and :gh:`87613`.)
+
+* Speed up iteration over asynchronous generators: values yielded to
+  ``async for`` no longer create and discard a :exc:`StopIteration` exception
+  at every nesting level. The ``async_generators`` pyperformance benchmark is
+  about 30% faster.
+  (Contributed by Shamil Abdulaev in :gh:`158304`.)
+
+
+ast
+---
+
+* AST nodes now store attributes inline with shared keys instead of
+  allocating a separate dictionary for each node. Benchmarks of this
+  change measured about 16% faster :func:`ast.parse` calls and 52% less
+  memory used by the resulting ASTs.
+  (Contributed by Lysandros Nikolaou and Pablo Galindo Salgado
+  in :gh:`153568`.)
+
+
 datetime and time
 -----------------
 
@@ -1344,6 +1422,25 @@ Build changes
 
   (Contributed by Stan Ulbrych, Florian Mayer and AnnaAr321 in :gh:`156049`.)
 
+* iOS builds can now be configured as free-threaded or debug builds.
+
+  (Contributed by Russell Keith-Magee in :gh:`159385`.)
+
+
+.. _whatsnew316-apple-platforms:
+
+Build support for tvOS, watchOS, and visionOS
+---------------------------------------------
+
+Added build support for Apple's tvOS, watchOS, and visionOS.
+These platforms are not currently included in the supported
+platform tiers defined by :pep:`11`.
+See the :source:`tvOS <Platforms/Apple/tvOS/README.md>`,
+:source:`watchOS <Platforms/Apple/watchOS/README.md>`, and
+:source:`visionOS <Platforms/Apple/visionOS/README.md>` build instructions.
+
+(Contributed by Russell Keith-Magee in :gh:`131999`.)
+
 
 C API changes
 =============