Install Python 3.9

About Python 3.9

Python is a programming language that lets you work more quickly and integrate your systems more effectively.

What's new in 3.9.13

Core and Builtins - gh-92311: Fixed a bug where setting frame.f_lineno to jump over a list comprehension could misbehave or crash. - gh-92112: Fix crash triggered by an evil custom mro() on a metaclass. - gh-92036: Fix a crash in subinterpreters related to the garbage collector. When a subinterpreter is deleted, untrack all objects tracked by its GC. To prevent a crash in deallocator functions expecting objects to be tracked by the GC, leak a strong reference to these objects on purpose, so they are never deleted and their deallocator functions are not called. Patch by Victor Stinner. - gh-91421: Fix a potential integer overflow in _Py_DecodeUTF8Ex. - bpo-46775: Some Windows system error codes(>= 10000) are now mapped into the correct errno and may now raise a subclass of OSError. Patch by Dong-hee Na. - bpo-46962: Classes and functions that unconditionally declared their docstrings ignoring the --without-doc-strings compilation flag no longer do so. The classes affected are pickle.PickleBuffer, testcapi.RecursingInfinitelyError, and types.GenericAlias. The functions affected are 24 methods in ctypes. Patch by Oleg Iarygin. - bpo-36819: Fix crashes in built-in encoders with error handlers that return position less or equal than the starting position of non-encodable characters. Library - gh-91581: utcfromtimestamp() no longer attempts to resolve fold in the pure Python implementation, since the fold is never 1 in UTC. In addition to being slightly faster in the common case, this also prevents some errors when the timestamp is close to datetime.min. Patch by Paul Ganssle. -...

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