shutil.make_archive

In previous versions of shutil.make_archive, we needed to temporarily switch the current working directory to archive file/directory (e.g. zip, tar, bztar, xztar, etc.) to its relative paths - similar to the following shell pattern:

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(
  cd /path/to/archive && { archive }
)

Now we can just pass the new root_dir argument.

tempfile.NamedTemporaryFile’s delete_on_close

This is one of my favorite new features. In UNIX, the tempfile.NamedTemporaryFile generates a random file under the /tmp directory to facilitate ephemeral writes and reads (like caching). However, in the old days, we needed to keep track of the filenames if we ever wanted to manually delete them. With the new delete_on_close boolean parameter, we can now offload this responsibility with .close().

os.PIDFD_NONBLOCK

In this version, a new flag to os.pidfd_open(pid: int, flags: int) has been added to expose PIDFD_NONBLOCK to Python (a.k.a. opening a file descriptor to a running process in a non-blocking mode).

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// Modules/posixmodule.c

#ifdef PIDFD_NONBLOCK
    if (PyModule_AddIntMacro(m, PIDFD_NONBLOCK)) return -1;
#endif

Not sure what I’ll be using this for yet, but will be keeping it in mind.

math.sumprod

Instead of doing this:

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p = [1, 2, 3, 4, 5]
q = [5, 4, 3, 2, 1]

sum(list(map(lambda x, y: x * y, p, q)))  # 35

We can just do this:

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p = [1, 2, 3, 4, 5]
q = [5, 4, 3, 2, 1]

math.sumprod(p, q)  # 35

typing.Hashable and typing.Sized

I use these type hint notations in my codebase - but with 3.12, the naming convention has been changed to collections.abc.Hashable and collections.abc.Sized.

get_event_loop()

The asyncio.get_event_loop(), which returns the event loop of the current async context, will now DeprecationWarning if there is no context event loop.

typing.runtime_checkable

The runtime_checkable decorator will now freeze the members of typing.Protocol.

wstr and wstr_length

From Unicode objects, the wstr and wstr_length have been removed. This reduces the object size by 8 or 16 Bytes on 64-bit platforms.

re.sub

Great news for regular expression lovers like myself! Regex-based substitutions will be faster by 2~3x for expressions containing group references (like \1).

perf

The perf profilers will now report function names in the trace logs.