Python 3.9 有什麼新功能

編輯者:

Łukasz Langa

本文介紹了 Python 3.9 與 3.8 相比多了哪些新功能。Python 3.9 已於 2020 年 10 月 5 日發布。有關完整詳細資訊，請參閱 changelog。

也參考

PEP 596 - Python 3.9 發佈時程

發布重點摘要

新增語法特性：

  • PEP 584, union operators added to dict;

  • PEP 585, type hinting generics in standard collections;

  • PEP 614, relaxed grammar restrictions on decorators.

新的內建功能：

  • PEP 616, string methods to remove prefixes and suffixes.

New features in the standard library:

  • PEP 593, flexible function and variable annotations;

  • os.pidfd_open() added that allows process management without races and signals.

直譯器的改進：

  • PEP 573, fast access to module state from methods of C extension types;

  • PEP 617, CPython now uses a new parser based on PEG;

  • a number of Python builtins (range, tuple, set, frozenset, list, dict) are now sped up using PEP 590 vectorcall;

  • garbage collection does not block on resurrected objects;

  • a number of Python modules (_abc, audioop, _bz2, _codecs, _contextvars, _crypt, _functools, _json, _locale, math, operator, resource, time, _weakref) now use multiphase initialization as defined by PEP 489;

  • a number of standard library modules (audioop, ast, grp, _hashlib, pwd, _posixsubprocess, random, select, struct, termios, zlib) are now using the stable ABI defined by PEP 384.

新的函式庫模組：

  • PEP 615, the IANA Time Zone Database is now present in the standard library in the zoneinfo module;

  • an implementation of a topological sort of a graph is now provided in the new