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Diffstat (limited to 'Doc/whatsnew/3.10.rst')
| -rw-r--r-- | Doc/whatsnew/3.10.rst | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/Doc/whatsnew/3.10.rst b/Doc/whatsnew/3.10.rst index 1228f26954..738ef974e7 100644 --- a/Doc/whatsnew/3.10.rst +++ b/Doc/whatsnew/3.10.rst @@ -70,6 +70,23 @@ Summary -- Release highlights New Features ============ +.. _whatsnew310-pep563: + +PEP 563: Postponed Evaluation of Annotations Becomes Default +------------------------------------------------------------ + +In Python 3.7, postponed evaluation of annotations was added, +to be enabled with a ``from __future__ import annotations`` +directive. In 3.10 this became the default behavior, even +without that future directive. With this being default, all +annotations stored in :attr:`__annotations__` will be strings. +If needed, annotations can be resolved at runtime using +:func:`typing.get_type_hints`. See :pep:`563` for a full +description. Also, the :func:`inspect.signature` will try to +resolve types from now on, and when it fails it will fall back to +showing the string annotations. (Contributed by Batuhan Taskaya +in :issue:`38605`.) + * The :class:`int` type has a new method :meth:`int.bit_count`, returning the number of ones in the binary expansion of a given integer, also known as the population count. (Contributed by Niklas Fiekas in :issue:`29882`.) @@ -82,6 +99,50 @@ New Features * :pep:`618`: The :func:`zip` function now has an optional ``strict`` flag, used to require that all the iterables have an equal length. +PEP 613: TypeAlias Annotation +----------------------------- + +:pep:`484` introduced the concept of type aliases, only requiring them to be +top-level unannotated assignments. This simplicity sometimes made it difficult +for type checkers to distinguish between type aliases and ordinary assignments, +especially when forward references or invalid types were involved. Compare:: + + StrCache = 'Cache[str]' # a type alias + LOG_PREFIX = 'LOG[DEBUG]' # a module constant + +Now the :mod:`typing` module has a special annotation :data:`TypeAlias` to +declare type aliases more explicitly:: + + StrCache: TypeAlias = 'Cache[str]' # a type alias + LOG_PREFIX = 'LOG[DEBUG]' # a module constant + +See :pep:`613` for more details. + +(Contributed by Mikhail Golubev in :issue:`41923`.) + +PEP604: New Type Union Operator +------------------------------- + +A new type union operator was introduced which enables the syntax ``X | Y``. +This provides a cleaner way of expressing 'either type X or type Y' instead of +using :data:`typing.Union`, especially in type hints (annotations). + +In previous versions of Python, to apply a type hint for functions accepting +arguments of multiple types, :data:`typing.Union` was used:: + + def square(number: Union[int, float]) -> Union[int, float]: + return number ** 2 + + +Now, type hints can be written in a more succinct manner:: + + def square(number: int | float) -> int | float: + return number ** 2 + + +See :pep:`604` for more details. + +(Contributed by Maggie Moss and Philippe Prados in :issue:`41428`.) Other Language Changes ====================== @@ -109,6 +170,12 @@ base64 Add :func:`base64.b32hexencode` and :func:`base64.b32hexdecode` to support the Base32 Encoding with Extended Hex Alphabet. +codecs +------ + +Add a :func:`codecs.unregister` function to unregister a codec search function. +(Contributed by Hai Shi in :issue:`41842`.) + curses ------ @@ -119,6 +186,11 @@ by :func:`curses.color_content`, :func:`curses.init_color`, support is provided by the underlying ncurses library. (Contributed by Jeffrey Kintscher and Hans Petter Jansson in :issue:`36982`.) +encodings +--------- +:func:`encodings.normalize_encoding` now ignores non-ASCII characters. +(Contributed by Hai Shi in :issue:`39337`.) + glob ---- @@ -188,6 +260,12 @@ Deprecated Removed ======= +* Removed special methods ``__int__``, ``__float__``, ``__floordiv__``, + ``__mod__``, ``__divmod__``, ``__rfloordiv__``, ``__rmod__`` and + ``__rdivmod__`` of the :class:`complex` class. They always raised + a :exc:`TypeError`. + (Contributed by Serhiy Storchaka in :issue:`41974`.) + * The ``ParserBase.error()`` method from the private and undocumented ``_markupbase`` module has been removed. :class:`html.parser.HTMLParser` is the only subclass of ``ParserBase`` and its ``error()`` implementation has already been removed in @@ -237,6 +315,14 @@ New Features :class:`datetime.time` objects. (Contributed by Zackery Spytz in :issue:`30155`.) +* Add a :c:func:`PyCodec_Unregister` function to unregister a codec + search function. + (Contributed by Hai Shi in :issue:`41842`.) + +* The :c:func:`PyIter_Send` function was added to allow + sending value into iterator without raising ``StopIteration`` exception. + (Contributed by Vladimir Matveev in :issue:`41756`.) + Porting to Python 3.10 ---------------------- @@ -289,6 +375,14 @@ Porting to Python 3.10 Unicode object without initial data. (Contributed by Inada Naoki in :issue:`36346`.) +Deprecated +---------- + +* The ``PyUnicode_InternImmortal()`` function is now deprecated + and will be removed in Python 3.12: use :c:func:`PyUnicode_InternInPlace` + instead. + (Contributed by Victor Stinner in :issue:`41692`.) + Removed ------- @@ -324,3 +418,8 @@ Removed * Removed ``_Py_CheckRecursionLimit`` variable: it has been replaced by ``ceval.recursion_limit`` of the :c:type:`PyInterpreterState` structure. (Contributed by Victor Stinner in :issue:`41834`.) + +* Removed undocumented macros ``Py_ALLOW_RECURSION`` and + ``Py_END_ALLOW_RECURSION`` and the ``recursion_critical`` field of the + :c:type:`PyInterpreterState` structure. + (Contributed by Serhiy Storchaka in :issue:`41936`.) |