Python 3.9 is available. What’s new:
New syntax features:
- PEP 584, union operators added to
dict; - PEP 585, type hinting generics in standard collections;
- PEP 614, relaxed grammar restrictions on decorators.
New built-in features:
- 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.
Interpreter improvements:
- 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.
New library modules:
- PEP 615, the IANA Time Zone Database is now present in the standard library in the
zoneinfomodule; - an implementation of a topological sort of a graph is now provided in the new
graphlibmodule.
Release process changes:
- PEP 602, CPython adopts an annual release cycle.
Firefox