239 lines
27 KiB
ReStructuredText
239 lines
27 KiB
ReStructuredText
.. _python_310:
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Python 3.10
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===========
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Python 3.10.0 (final) was released on the 4 October 2021. The Features for 3.10 are
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defined in `PEP 619 <https://www.python.org/dev/peps/pep-0619/#features-for-3-10>`_
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and a detailed description of the changes can be found in
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`What's New in Python 3.10 <https://docs.python.org/3/whatsnew/3.10.html>`_.
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.. table::
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:widths: 20 60 20
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+--------------------------------------------------------+----------------------------------------------------+--------------+
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| **New syntax features** | **Status** |
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+--------------------------------------------------------+----------------------------------------------------+--------------+
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| `PEP 634 <https://www.python.org/dev/peps/pep-0634/>`_ | Structural Pattern Matching: Specification | [#spm]_ |
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+--------------------------------------------------------+----------------------------------------------------+--------------+
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| `PEP 635 <https://www.python.org/dev/peps/pep-0635/>`_ | Structural Pattern Matching: Motivation and | [#spm]_ |
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| | Rationale | |
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+--------------------------------------------------------+----------------------------------------------------+--------------+
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| `PEP 636 <https://www.python.org/dev/peps/pep-0636/>`_ | Structural Pattern Matching: Tutorial | [#spm]_ |
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+--------------------------------------------------------+----------------------------------------------------+--------------+
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| `bpo-12782 | Parenthesized context managers are now officially | |
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| <https://github.com/python/cpython/issues/56991>`_ | allowed | |
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+--------------------------------------------------------+----------------------------------------------------+--------------+
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| **New features in the standard library** |
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+--------------------------------------------------------+----------------------------------------------------+--------------+
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| `PEP 618 <https://www.python.org/dev/peps/pep-0618/>`_ | Add Optional Length-Checking To zip | |
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+--------------------------------------------------------+----------------------------------------------------+--------------+
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| **Interpreter improvements** |
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+--------------------------------------------------------+----------------------------------------------------+--------------+
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| `PEP 626 <https://www.python.org/dev/peps/pep-0626/>`_ | Precise line numbers for debugging and other tools | |
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+--------------------------------------------------------+----------------------------------------------------+--------------+
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| **New typing features** |
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+--------------------------------------------------------+----------------------------------------------------+--------------+
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| `PEP 604 <https://www.python.org/dev/peps/pep-0604/>`_ | Allow writing union types as X | Y | |
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+--------------------------------------------------------+----------------------------------------------------+--------------+
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| `PEP 613 <https://www.python.org/dev/peps/pep-0613/>`_ | Explicit Type Aliases | |
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+--------------------------------------------------------+----------------------------------------------------+--------------+
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| `PEP 612 <https://www.python.org/dev/peps/pep-0612/>`_ | Parameter Specification Variables | |
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+--------------------------------------------------------+----------------------------------------------------+--------------+
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| **Important deprecations, removals or restrictions** |
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+--------------------------------------------------------+----------------------------------------------------+--------------+
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| `PEP 644 <https://www.python.org/dev/peps/pep-0644/>`_ | Require OpenSSL 1.1.1 or newer | |
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+--------------------------------------------------------+----------------------------------------------------+--------------+
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| `PEP 632 <https://www.python.org/dev/peps/pep-0632/>`_ | Deprecate distutils module. | Not relevant |
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+--------------------------------------------------------+----------------------------------------------------+--------------+
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| `PEP 623 <https://www.python.org/dev/peps/pep-0623/>`_ | Deprecate and prepare for the removal of the wstr | Not relevant |
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| | member in PyUnicodeObject. | |
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+--------------------------------------------------------+----------------------------------------------------+--------------+
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| `PEP 624 <https://www.python.org/dev/peps/pep-0624/>`_ | Remove Py_UNICODE encoder APIs | Not relevant |
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+--------------------------------------------------------+----------------------------------------------------+--------------+
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| `PEP 597 <https://www.python.org/dev/peps/pep-0597/>`_ | Add optional EncodingWarning | |
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+--------------------------------------------------------+----------------------------------------------------+--------------+
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Other Language Changes:
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.. table::
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:widths: 90 10
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+-------------------------------------------------------------------------------------------------------------+---------------+
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| The :class:`int` type has a new method :meth:`int.bit_count`, returning the | |
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| number of ones in the binary expansion of a given integer, also known | |
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| as the population count. | |
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+-------------------------------------------------------------------------------------------------------------+---------------+
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| The views returned by :meth:`dict.keys`, :meth:`dict.values` and | |
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| :meth:`dict.items` now all have a ``mapping`` attribute that gives a | |
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| :class:`types.MappingProxyType` object wrapping the original | |
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| dictionary. | |
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+-------------------------------------------------------------------------------------------------------------+---------------+
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| :pep:`618`: The :func:`zip` function now has an optional ``strict`` flag, used | |
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| to require that all the iterables have an equal length. | |
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+-------------------------------------------------------------------------------------------------------------+---------------+
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| Builtin and extension functions that take integer arguments no longer accept | |
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| :class:`~decimal.Decimal`\ s, :class:`~fractions.Fraction`\ s and other | |
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| objects that can be converted to integers only with a loss (e.g. that have | |
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| the :meth:`~object.__int__` method but do not have the | |
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| :meth:`~object.__index__` method). | |
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+-------------------------------------------------------------------------------------------------------------+---------------+
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| If :func:`object.__ipow__` returns :const:`NotImplemented`, the operator will | |
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| correctly fall back to :func:`object.__pow__` and :func:`object.__rpow__` as expected. | |
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+-------------------------------------------------------------------------------------------------------------+---------------+
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| Assignment expressions can now be used unparenthesized within set literals | |
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| and set comprehensions, as well as in sequence indexes (but not slices). | |
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+-------------------------------------------------------------------------------------------------------------+---------------+
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| Functions have a new ``__builtins__`` attribute which is used to look for | |
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| builtin symbols when a function is executed, instead of looking into | |
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| ``__globals__['__builtins__']``. The attribute is initialized from | |
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| ``__globals__["__builtins__"]`` if it exists, else from the current builtins. | |
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+-------------------------------------------------------------------------------------------------------------+---------------+
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| Two new builtin functions -- :func:`aiter` and :func:`anext` have been added | |
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| to provide asynchronous counterparts to :func:`iter` and :func:`next`, | |
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| respectively. | |
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+-------------------------------------------------------------------------------------------------------------+---------------+
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| Static methods (:func:`@staticmethod <staticmethod>`) and class methods | |
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| (:func:`@classmethod <classmethod>`) now inherit the method attributes | |
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| (``__module__``, ``__name__``, ``__qualname__``, ``__doc__``, | |
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| ``__annotations__``) and have a new ``__wrapped__`` attribute. | |
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| Moreover, static methods are now callable as regular functions. | |
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+-------------------------------------------------------------------------------------------------------------+---------------+
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| Annotations for complex targets (everything beside ``simple name`` targets | |
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| defined by :pep:`526`) no longer cause any runtime effects with ``from __future__ import annotations``. | |
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+-------------------------------------------------------------------------------------------------------------+---------------+
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| Class and module objects now lazy-create empty annotations dicts on demand. | |
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| The annotations dicts are stored in the object’s ``__dict__`` for | |
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| backwards compatibility. This improves the best practices for working | |
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| with ``__annotations__``. | |
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+-------------------------------------------------------------------------------------------------------------+---------------+
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| Annotations consist of ``yield``, ``yield from``, ``await`` or named expressions | |
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| are now forbidden under ``from __future__ import annotations`` due to their side | |
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| effects. | |
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+-------------------------------------------------------------------------------------------------------------+---------------+
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| Usage of unbound variables, ``super()`` and other expressions that might | |
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| alter the processing of symbol table as annotations are now rendered | |
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| effectless under ``from __future__ import annotations``. | |
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+-------------------------------------------------------------------------------------------------------------+---------------+
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| Hashes of NaN values of both :class:`float` type and | |
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| :class:`decimal.Decimal` type now depend on object identity. Formerly, they | |
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| always hashed to ``0`` even though NaN values are not equal to one another. | |
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| This caused potentially quadratic runtime behavior due to excessive hash | |
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| collisions when creating dictionaries and sets containing multiple NaNs. | |
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+-------------------------------------------------------------------------------------------------------------+---------------+
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| A :exc:`SyntaxError` (instead of a :exc:`NameError`) will be raised when deleting | |
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| the :const:`__debug__` constant. | |
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+-------------------------------------------------------------------------------------------------------------+---------------+
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| :exc:`SyntaxError` exceptions now have ``end_lineno`` and | |
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| ``end_offset`` attributes. They will be ``None`` if not determined. | |
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+-------------------------------------------------------------------------------------------------------------+---------------+
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Changes to built-in modules:
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.. table::
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:widths: 90 10
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| `asyncio <https://docs.python.org/3/whatsnew/3.10.html#asyncio>`_ |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| Add missing :meth:`~asyncio.events.AbstractEventLoop.connect_accepted_socket` | |
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| method. | |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| `array <https://docs.python.org/3/whatsnew/3.10.html#array>`_ |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| The :meth:`~array.array.index` method of :class:`array.array` now has | |
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| optional *start* and *stop* parameters. | |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| `gc <https://docs.python.org/3/whatsnew/3.10.html#gc>`_ |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| Add audit hooks for :func:`gc.get_objects`, :func:`gc.get_referrers` and | |
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| :func:`gc.get_referents`. | |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| `hashlib <https://docs.python.org/3/whatsnew/3.10.html#hashlib>`_ |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| The hashlib module requires OpenSSL 1.1.1 or newer. | |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| The hashlib module has preliminary support for OpenSSL 3.0.0. | |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| The pure-Python fallback of :func:`~hashlib.pbkdf2_hmac` is deprecated. In | |
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| the future PBKDF2-HMAC will only be available when Python has been built with | |
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| OpenSSL support. | |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| `os <https://docs.python.org/3/whatsnew/3.10.html#os>`_ |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| Add :func:`os.cpu_count()` support for VxWorks RTOS. | |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| Add a new function :func:`os.eventfd` and related helpers to wrap the | |
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| ``eventfd2`` syscall on Linux. | |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| Add :func:`os.splice()` that allows to move data between two file | |
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| descriptors without copying between kernel address space and user | |
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| address space, where one of the file descriptors must refer to a | |
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| pipe. | |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| Add :data:`~os.O_EVTONLY`, :data:`~os.O_FSYNC`, :data:`~os.O_SYMLINK` | |
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| and :data:`~os.O_NOFOLLOW_ANY` for macOS. | |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| `platform <https://docs.python.org/3/whatsnew/3.10.html#platform>`_ |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| Add :func:`platform.freedesktop_os_release()` to retrieve operation system | |
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| identification from `freedesktop.org os-release | |
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| <https://www.freedesktop.org/software/systemd/man/os-release.html>`_ standard file. | |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| `socket <https://docs.python.org/3/whatsnew/3.10.html#socket>`_ |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| The exception :exc:`socket.timeout` is now an alias of :exc:`TimeoutError`. | |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| Add option to create MPTCP sockets with ``IPPROTO_MPTCP``. | |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| Add ``IP_RECVTOS`` option to receive the type of service (ToS) or DSCP/ECN fields. | |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| `ssl <https://docs.python.org/3/whatsnew/3.10.html#ssl>`_ |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| The ssl module requires OpenSSL 1.1.1 or newer. | |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| The ssl module has preliminary support for OpenSSL 3.0.0 and new option | |
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| :data:`~ssl.OP_IGNORE_UNEXPECTED_EOF`. | |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| Deprecated function and use of deprecated constants now result in | |
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| a :exc:`DeprecationWarning`. :attr:`ssl.SSLContext.options` has | |
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| :data:`~ssl.OP_NO_SSLv2` and :data:`~ssl.OP_NO_SSLv3` set by default and | |
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| therefore cannot warn about setting the flag again. | |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| The ssl module now has more secure default settings. Ciphers without forward | |
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| secrecy or SHA-1 MAC are disabled by default. Security level 2 prohibits | |
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| weak RSA, DH, and ECC keys with less than 112 bits of security. | |
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| :class:`~ssl.SSLContext` defaults to minimum protocol version TLS 1.2. | |
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| Settings are based on Hynek Schlawack's research. | |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| The deprecated protocols SSL 3.0, TLS 1.0, and TLS 1.1 are no longer | |
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| officially supported. Python does not block them actively. However | |
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| OpenSSL build options, distro configurations, vendor patches, and cipher | |
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| suites may prevent a successful handshake. | |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| Add a *timeout* parameter to the :func:`ssl.get_server_certificate` function. | |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| The ssl module uses heap-types and multi-phase initialization. | |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| A new verify flag :data:`~ssl.VERIFY_X509_PARTIAL_CHAIN` has been added. | |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| `sys <https://docs.python.org/3/whatsnew/3.10.html#sys>`_ |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| Add :data:`sys.orig_argv` attribute: the list of the original command line | |
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| arguments passed to the Python executable. | |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| Add :data:`sys.stdlib_module_names`, containing the list of the standard library | |
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| module names. | |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| `_thread <https://docs.python.org/3/whatsnew/3.10.html#_thread>`_ |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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| :func:`_thread.interrupt_main` now takes an optional signal number to | |
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| simulate (the default is still :data:`signal.SIGINT`). | |
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+---------------------------------------------------------------------------------------------------------------+---------------+
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.. rubric:: Notes
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.. [#spm] The structural pattern matching feature is discussed in `issue #7847 <https://github.com/micropython/micropython/issues/7847>`_.
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