Skip to content

gh-133879: Copyedit "What's new in Python 3.15" #148686

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
hugovk wants to merge 14 commits into
base: main
Choose a base branch
from
+66 −68
Open

gh-133879: Copyedit "What's new in Python 3.15" #148686

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
14 commits
Select commit Hold shift + click to select a range
3ddaec9
Use toml syntax highlights now Pygments 2.20 is out
hugovk Mar 29, 2026
e3a04f6
Move pprint addition from 'Removals' to 'Improved modules'
hugovk Apr 9, 2026
9ad0a64
Move typing removal from 'New deprecations' to 'Removals'
hugovk Apr 9, 2026
6d10425
Link to issue
hugovk Apr 15, 2026
de0fac4
a-z
hugovk Apr 15, 2026
9313755
Wording
hugovk Apr 17, 2026
5532ef6
Fullstops
hugovk Apr 17, 2026
bd524f9
Spacing
hugovk Apr 17, 2026
373386f
Deduplicate PR numbers
hugovk Apr 17, 2026
03c1a5a
& -> and
hugovk Apr 17, 2026
80f9e1b
Move improved error messages
hugovk Apr 17, 2026
3a6375a
Use pytb lexer for exceptions
hugovk Apr 17, 2026
e54c347
Move improved error messages
hugovk Apr 17, 2026
3278ac8
Fix indents
hugovk Apr 17, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion Doc/deprecations/pending-removal-in-3.17.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -35,7 +35,7 @@ Pending removal in Python 3.17

- Passing non-ascii *encoding* names to :func:`encodings.normalize_encoding`
is deprecated and scheduled for removal in Python 3.17.
(Contributed by Stan Ulbrych in :gh:`136702`)
(Contributed by Stan Ulbrych in :gh:`136702`.)

* :mod:`typing`:

Expand Down
132 changes: 65 additions & 67 deletions Doc/whatsnew/3.15.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -141,7 +141,7 @@ In the case where loading a lazily imported module fails (for example, if
the module does not exist), Python raises the exception at the point of
first use rather than at import time. The associated traceback includes both
the location where the name was accessed and the original import statement,
making it straightforward to diagnose & debug the failure.
making it straightforward to diagnose and debug the failure.

For cases where you want to enable lazy loading globally without modifying
source code, Python provides the :option:`-X lazy_imports <-X>` command-line
Expand Down Expand Up @@ -450,14 +450,36 @@ Improved error messages

Running this code now produces a clearer suggestion:

.. code-block:: pycon
.. code-block:: pytb

Traceback (most recent call last):
File "/home/pablogsal/github/python/main/lel.py", line 42, in <module>
print(container.area)
^^^^^^^^^^^^^^
File "/home/pablogsal/github/python/main/lel.py", line 42, in <module>
print(container.area)
^^^^^^^^^^^^^^
AttributeError: 'Container' object has no attribute 'area'. Did you mean '.inner.area' instead of '.area'?

* The interpreter now tries to provide a suggestion when
:func:`delattr` fails due to a missing attribute.
When an attribute name that closely resembles an existing attribute is used,
the interpreter will suggest the correct attribute name in the error message.
For example:

.. doctest::

>>> class A:
... pass
>>> a = A()
>>> a.abcde = 1
>>> del a.abcdf # doctest: +ELLIPSIS
Traceback (most recent call last):
...
AttributeError: 'A' object has no attribute 'abcdf'. Did you mean: 'abcde'?

(Contributed by Nikita Sobolev and Pranjal Prajapati in :gh:`136588`.)

* Several error messages incorrectly using the term "argument" have been corrected.
(Contributed by Stan Ulbrych in :gh:`133382`.)


Other language changes
======================
Expand Down Expand Up @@ -489,28 +511,6 @@ Other language changes

(Contributed by Adam Turner in :gh:`133711`; PEP 686 written by Inada Naoki.)

* Several error messages incorrectly using the term "argument" have been corrected.
(Contributed by Stan Ulbrych in :gh:`133382`.)

* The interpreter now tries to provide a suggestion when
:func:`delattr` fails due to a missing attribute.
When an attribute name that closely resembles an existing attribute is used,
the interpreter will suggest the correct attribute name in the error message.
For example:

.. doctest::

>>> class A:
... pass
>>> a = A()
>>> a.abcde = 1
>>> del a.abcdf # doctest: +ELLIPSIS
Traceback (most recent call last):
...
AttributeError: 'A' object has no attribute 'abcdf'. Did you mean: 'abcde'?

(Contributed by Nikita Sobolev and Pranjal Prajapati in :gh:`136588`.)

* Unraisable exceptions are now highlighted with color by default. This can be
controlled by :ref:`environment variables <using-on-controlling-color>`.
(Contributed by Peter Bierma in :gh:`134170`.)
Expand Down Expand Up @@ -707,7 +707,7 @@ base64
(Contributed by Serhiy Storchaka in :gh:`143214` and :gh:`146431`.)

* Added the *ignorechars* parameter in :func:`~base64.b16decode`,
:func:`~base64.b32decode`, :func:`~base64.b32hexdecode`,
:func:`~base64.b32decode`, :func:`~base64.b32hexdecode`,
:func:`~base64.b64decode`, :func:`~base64.b85decode`, and
:func:`~base64.z85decode`.
(Contributed by Serhiy Storchaka in :gh:`144001` and :gh:`146431`.)
Expand Down Expand Up @@ -879,13 +879,13 @@ inspect
json
----

* Add the *array_hook* parameter to :func:`~json.load` and
* Add the *array_hook* parameter to :func:`~json.load` and
:func:`~json.loads` functions:
allow a callback for JSON literal array types to customize Python lists in
the resulting decoded object. Passing combined :class:`frozendict` to
*object_pairs_hook* param and :class:`tuple` to ``array_hook`` will yield a
deeply nested immutable Python structure representing the JSON data.
(Contributed by Joao S. O. Bueno in :gh:`146440`)
(Contributed by Joao S. O. Bueno in :gh:`146440`.)


locale
Expand Down Expand Up @@ -978,6 +978,20 @@ pickle
(Contributed by Zackery Spytz and Serhiy Storchaka in :gh:`77188`.)


pprint
------

* Add an *expand* keyword argument for :func:`pprint.pprint`,
:func:`pprint.pformat`, :func:`pprint.pp`. If true, the output will be
formatted similar to pretty-printed :func:`json.dumps` when
*indent* is supplied.
(Contributed by Stefan Todoran, Semyon Moroz and Hugo van Kemenade in
:gh:`112632`.)

* Add t-string support to :mod:`pprint`.
(Contributed by Loïc Simon and Hugo van Kemenade in :gh:`134551`.)


re
--

Expand Down Expand Up @@ -1099,7 +1113,7 @@ subprocess

If none of these mechanisms are available, the function falls back to the
traditional busy loop (non-blocking call and short sleeps).
(Contributed by Giampaolo Rodola in :gh:`83069`).
(Contributed by Giampaolo Rodola in :gh:`83069`.)


symtable
Expand Down Expand Up @@ -1156,7 +1170,7 @@ timeit

* Make the target time of :meth:`timeit.Timer.autorange` configurable
and add ``--target-time`` option to the command-line interface.
(Contributed by Alessandro Cucci and Miikka Koskinen in :gh:`140283`.)
(Contributed by Alessandro Cucci and Miikka Koskinen in :gh:`80642`.)


tkinter
Expand Down Expand Up @@ -1201,10 +1215,7 @@ tomllib
Previously an inline table had to be on a single line and couldn't end
with a trailing comma. This is now relaxed so that the following is valid:

.. syntax highlighting needs TOML 1.1.0 support in Pygments,
see https://github.com/pygments/pygments/issues/3026

.. code-block:: text
.. code-block:: toml

tbl = {
key = "a string",
Expand All @@ -1216,15 +1227,15 @@ tomllib
- Add ``\xHH`` notation to basic strings for codepoints under 255,
and the ``\e`` escape for the escape character:

.. code-block:: text
.. code-block:: toml

null = "null byte: \x00; letter a: \x61"
csi = "\e["

- Seconds in datetime and time values are now optional.
The following are now valid:

.. code-block:: text
.. code-block:: toml

dt = 2010-02-03 14:15
t = 14:15
Expand Down Expand Up @@ -1399,7 +1410,7 @@ Optimizations
=============

* ``mimalloc`` is now used as the default allocator for
for raw memory allocations such as via :c:func:`PyMem_RawMalloc`
raw memory allocations such as via :c:func:`PyMem_RawMalloc`
for better performance on :term:`free-threaded builds <free-threaded build>`.
(Contributed by Kumar Aditya in :gh:`144914`.)

Expand All @@ -1418,7 +1429,7 @@ base64 & binascii

* Implementation for Base32 has been rewritten in C.
Encoding and decoding is now two orders of magnitude faster.
(Contributed by James Seo in :gh:`146192`)
(Contributed by James Seo in :gh:`146192`.)


csv
Expand Down Expand Up @@ -1512,7 +1523,7 @@ The JIT compiler's machine code generator now produces better machine code
for x86-64 and AArch64 macOS and Linux targets. In general, users should
experience lower memory usage for generated machine code and more efficient
machine code versus 3.14.
(Contributed by Brandt Bucher in :gh:`136528` and :gh:`136528`.
(Contributed by Brandt Bucher in :gh:`136528` and :gh:`135905`.
Implementation for AArch64 contributed by Mark Shannon in :gh:`139855`.
Additional optimizations for AArch64 contributed by Mark Shannon and
Diego Russo in :gh:`140683` and :gh:`142305`.)
Expand All @@ -1535,6 +1546,14 @@ collections.abc
deprecated since Python 3.12, and is scheduled for removal in Python 3.17.


ctypes
------

* Removed the undocumented function :func:`!ctypes.SetPointerType`,
which has been deprecated since Python 3.13.
(Contributed by Bénédikt Tran in :gh:`133866`.)


datetime
--------

Expand All @@ -1544,14 +1563,6 @@ datetime
(Contributed by Stan Ulbrych and Gregory P. Smith in :gh:`70647`.)


ctypes
------

* Removed the undocumented function :func:`!ctypes.SetPointerType`,
which has been deprecated since Python 3.13.
(Contributed by Bénédikt Tran in :gh:`133866`.)


glob
----

Expand Down Expand Up @@ -1594,20 +1605,6 @@ platform
(Contributed by Alexey Makridenko in :gh:`133604`.)


pprint
------

* Add an *expand* keyword argument for :func:`pprint.pprint`,
:func:`pprint.pformat`, :func:`pprint.pp`. If true, the output will be
formatted similar to pretty-printed :func:`json.dumps` when
*indent* is supplied.
(Contributed by Stefan Todoran, Semyon Moroz and Hugo van Kemenade in
:gh:`112632`.)

* Add t-string support to :mod:`pprint`.
(Contributed by Loïc Simon and Hugo van Kemenade in :gh:`134551`.)


sre_*
-----

Expand Down Expand Up @@ -1650,6 +1647,9 @@ typing
or ``TD = TypedDict("TD", {})`` instead.
(Contributed by Bénédikt Tran in :gh:`133823`.)

* Deprecated :func:`!typing.no_type_check_decorator` has been removed.
(Contributed by Nikita Sobolev in :gh:`133601`.)


wave
----
Expand Down Expand Up @@ -1765,8 +1765,6 @@ New deprecations
:func:`issubclass`, but warnings were not previously emitted if it was
merely imported or accessed from the :mod:`!typing` module.

* Deprecated :func:`!typing.no_type_check_decorator` has been removed.
(Contributed by Nikita Sobolev in :gh:`133601`.)

* ``__version__``

Expand Down Expand Up @@ -2053,8 +2051,8 @@ Deprecated C APIs

- :c:macro:`Py_ALIGNED`: Prefer ``alignas`` instead.
- :c:macro:`PY_FORMAT_SIZE_T`: Use ``"z"`` directly.
- :c:macro:`Py_LL` & :c:macro:`Py_ULL`:
Use standard suffixes, ``LL`` & ``ULL``.
- :c:macro:`Py_LL` and :c:macro:`Py_ULL`:
Use standard suffixes, ``LL`` and ``ULL``.
- :c:macro:`PY_LONG_LONG`, :c:macro:`PY_LLONG_MIN`, :c:macro:`PY_LLONG_MAX`,
:c:macro:`PY_ULLONG_MAX`, :c:macro:`PY_INT32_T`, :c:macro:`PY_UINT32_T`,
:c:macro:`PY_INT64_T`, :c:macro:`PY_UINT64_T`, :c:macro:`PY_SIZE_MAX`:
Expand Down
Loading