diff --git a/Doc/whatsnew/3.11.rst b/Doc/whatsnew/3.11.rst index 79afc1f99e99d9..fe50e188933457 100644 --- a/Doc/whatsnew/3.11.rst +++ b/Doc/whatsnew/3.11.rst @@ -1128,33 +1128,52 @@ fcntl Optimizations ============= -* Compiler now optimizes simple C-style formatting with literal format - containing only format codes ``%s``, ``%r`` and ``%a`` and makes it as - fast as corresponding f-string expression. +This section covers specific optimizations independent of the +:ref:`whatsnew311-faster-cpython` project, which is covered in its own section. + +* The compiler now optimizes simple + :ref:`printf-style % formatting ` on string literals + containing only the format codes ``%s``, ``%r`` and ``%a`` and makes it as + fast as a corresponding :term:`f-string` expression. (Contributed by Serhiy Storchaka in :issue:`28307`.) -* "Zero-cost" exceptions are implemented. The cost of ``try`` statements is - almost eliminated when no exception is raised. - (Contributed by Mark Shannon in :issue:`40222`.) +* Integer division (``//``) is better tuned for optimization by compilers. + It is now around 20% faster on x86-64 when dividing an :class:`int` + by a value smaller than ``2**30``. + (Contributed by Gregory P. Smith and Tim Peters in :gh:`90564`.) -* Pure ASCII strings are now normalized in constant time by :func:`unicodedata.normalize`. - (Contributed by Dong-hee Na in :issue:`44987`.) +* :func:`sum` is now nearly 30% faster for integers smaller than ``2**30``. + (Contributed by Stefan Behnel in :gh:`68264`.) -* :mod:`math` functions :func:`~math.comb` and :func:`~math.perm` are now up - to 10 times or more faster for large arguments (the speed up is larger for - larger *k*). - (Contributed by Serhiy Storchaka in :issue:`37295`.) +* Resizing lists is streamlined for the common case, + speeding up :meth:`list.append` by ≈15% + and simple :term:`list comprehension`\s by up to 20-30% + (Contributed by Dennis Sweeney in :gh:`91165`.) -* Dict don't store hash value when all inserted keys are Unicode objects. - This reduces dict size. For example, ``sys.getsizeof(dict.fromkeys("abcdefg"))`` - becomes 272 bytes from 352 bytes on 64bit platform. +* Dictionaries don't store hash values when all keys are Unicode objects, + decreasing :class:`dict` size. + For example, ``sys.getsizeof(dict.fromkeys("abcdefg"))`` + is reduced from 352 bytes to 272 bytes (23% smaller) on 64-bit platforms. (Contributed by Inada Naoki in :issue:`46845`.) -* :mod:`re`'s regular expression matching engine has been partially refactored, - and now uses computed gotos (or "threaded code") on supported platforms. As a - result, Python 3.11 executes the `pyperformance regular expression benchmarks - `_ up to 10% - faster than Python 3.10. +* Using :class:`asyncio.DatagramProtocol` is now orders of magnitude faster + when transferring large files over UDP, + with speeds over 100 times higher for a ≈60 MiB file. + (Contributed by msoxzw in :gh:`91487`.) + +* :mod:`math` functions :func:`~math.comb` and :func:`~math.perm` are now + ≈10 times faster for large arguments (with a larger speedup for larger *k*). + (Contributed by Serhiy Storchaka in :issue:`37295`.) + +* The :mod:`statistics` functions :func:`~statistics.mean`, + :func:`~statistics.variance` and :func:`~statistics.stdev` now consume + iterators in one pass rather than converting them to a :class:`list` first. + This is twice as fast and can save substantial memory. + (Contributed by Raymond Hettinger in :gh:`90415`.) + +* :func:`unicodedata.normalize` + now normalizes pure-ASCII strings in constant time. + (Contributed by Dong-hee Na in :issue:`44987`.) .. _whatsnew311-faster-cpython: