diff options
Diffstat (limited to 'Doc/whatsnew')
| -rw-r--r-- | Doc/whatsnew/3.6.rst | 30 |
1 files changed, 26 insertions, 4 deletions
diff --git a/Doc/whatsnew/3.6.rst b/Doc/whatsnew/3.6.rst index 925b5ff..801191c 100644 --- a/Doc/whatsnew/3.6.rst +++ b/Doc/whatsnew/3.6.rst @@ -295,7 +295,7 @@ function body. In Python 3.6 this restriction has been lifted, making it possible to define *asynchronous generators*:: async def ticker(delay, to): - """Yield numbers from 0 to `to` every `delay` seconds.""" + """Yield numbers from 0 to *to* every *delay* seconds.""" for i in range(to): yield i await asyncio.sleep(delay) @@ -490,7 +490,7 @@ between two moments in time for which local times are the same:: 07:00:00 UTC = 02:00:00 EST 0 The values of the :attr:`fold <datetime.datetime.fold>` attribute have the -value `0` all instances except those that represent the second +value ``0`` for all instances except those that represent the second (chronologically) moment in time in an ambiguous case. .. seealso:: @@ -741,6 +741,12 @@ Some smaller changes made to the core Python language are: before the first use of the affected name in the same scope. Previously this was a ``SyntaxWarning``. +* It is now possible to set a :ref:`special method <specialnames>` to + ``None`` to indicate that the corresponding operation is not available. + For example, if a class sets :meth:`__iter__` to ``None``, the class + is not iterable. + (Contributed by Andrew Barnert and Ivan Levkivskyi in :issue:`25958`.) + * Long sequences of repeated traceback lines are now abbreviated as ``"[Previous line repeated {count} more times]"`` (see :ref:`whatsnew36-traceback` for an example). @@ -898,8 +904,13 @@ and :const:`cmath.nanj` to match the format used by complex repr. collections ----------- -The new :class:`~collections.Collection` abstract base class has been +The new :class:`~collections.abc.Collection` abstract base class has been added to represent sized iterable container classes. +(Contributed by Ivan Levkivskyi, docs by Neil Girdhar in :issue:`27598`.) + +The new :class:`~collections.abc.Reversible` abstract base class represents +iterable classes that also provide the :meth:`__reversed__`. +(Contributed by Ivan Levkivskyi in :issue:`25987`.) The :func:`~collections.namedtuple` function now accepts an optional keyword argument *module*, which, when specified, is used for @@ -1509,6 +1520,12 @@ Since the :mod:`typing` module was :term:`provisional <provisional api>` in Python 3.5, all changes introduced in Python 3.6 have also been backported to Python 3.5.x. +The :mod:`typing` module has a much improved support for generic type +aliases. For example ``Dict[str, Tuple[S, T]]`` is now a valid +type annotation. +(Contributed by Guido van Rossum in `Github #195 +<https://github.com/python/typing/pull/195>`_.) + The :class:`typing.ContextManager` class has been added for representing :class:`contextlib.AbstractContextManager`. (Contributed by Brett Cannon in :issue:`25609`.) @@ -1692,12 +1709,17 @@ Optimizations * The :class:`Task <asyncio.tasks.Task>` now has an optimized C implementation. (Contributed by Yury Selivanov in :issue:`28544`.) +* Various implementation improvements in the :mod:`typing` module + (such as caching of generic types) allow up to 30 times performance + improvements and reduced memory footprint. + * The ASCII decoder is now up to 60 times as fast for error handlers ``surrogateescape``, ``ignore`` and ``replace`` (Contributed by Victor Stinner in :issue:`24870`). * The ASCII and the Latin1 encoders are now up to 3 times as fast for the - error handler ``surrogateescape`` (Contributed by Victor Stinner in :issue:`25227`). + error handler ``surrogateescape`` + (Contributed by Victor Stinner in :issue:`25227`). * The UTF-8 encoder is now up to 75 times as fast for error handlers ``ignore``, ``replace``, ``surrogateescape``, ``surrogatepass`` (Contributed |