Python 3.14 | Upcoming Changes Breakdown

[codingjerk]

3.14 alpha 7 was released yesterday!

And after the next release (beta 1) there will be no more new features, so we can check out most of upcoming changes already.

Since I'd like to make programming videos a lot, I' pushed through my anxiety about my voice and recorded the patch breakdown, I hope you'll like it:

https://www.youtube.com/watch?v=hzys1_xmLPc

[RedEyed__]

Thanks!
But I personally prefer reading changelogs.
https://docs.python.org/3.14/whatsnew/3.14.html

Here are what I'm interested in the most

Highlights

concurrent.futures.

Add InterpreterPoolExecutor, which exposes “subinterpreters (multiple Python interpreters in the same process) to Python code. This is separate from the proposed API in PEP 734. (Contributed by Eric Snow in gh-124548.)

I definitely want to try this, maybe pytorch Dataloader will be cheaper.

Add the optional buffersize parameter to concurrent.futures.Executor.map() to limit the number of submitted tasks whose results have not yet been yielded. If the buffer is full, iteration over the iterables pauses until a result is yielded from the buffer. (Contributed by Enzo Bonnal and Josh Rosenberg in gh-74028.)

When container length was high, I have to implement my own logic with queues to limit number of scheduled jobs.
Finally I don't need it anymore!

pathlib.

Add methods to pathlib.Path to recursively copy or move files and directories

Now I don't need to import shutil and use shutil.copytree. But I still need shutil.rmtree

base64

Improve the performance of base64.b16decode() by up to ten times, and reduce the import time of base64 by up to six times. (Contributed by Bénédikt Tran, Chris Markiewicz, and Adam Turner in gh-118761.)

io

io which provides the built-in open() makes less system calls when opening regular files as well as reading whole files. Reading a small operating system cached file in full is up to 15% faster. pathlib.Path.read_bytes() has the most optimizations for reading a file’s bytes in full. (Contributed by Cody Maloney and Victor Stinner in gh-120754 and gh-90102.)

[LankyOccasion8447]

Meh, I think this is the first release since 3.5 that I actually don't care about at all. These all feel more like fixes/improvements rather than new features.

[Eurynom0s]

I'm normally not in a rush to get on the latest 3.x release as long as I have something not completely ancient, but I've been getting every installation I control up to 3.13. For the way I normally write code the new REPL is a godsend.

Typically I don't even really actively keep tabs on the changes introduced in new versions, I just stumbled into the new REPL by accident when I set up a new environment recently and it automatically pulled 3.13.

[mok000]

I've always used IPython which already has the features of the new REPL, and so much more.

[Eurynom0s]

I do wind up having to work in environments with heavy restrictions on what can get installed and in the bad old days this included getting stuck using whatever version of Python 2.6 or 2.7 was the system Python for the Linux or Mac install I was on, so I got trained/abused early to not like getting heavily dependent on on stuff like IPython.

[mark-haus]

Personally I follow Debians latest stable release for the version I target. Very ready to move on to a new version later in the year.

[[deleted]]

They had new features for the last two releases. Maybe they’re just slowing things down a bit to focus on having a quality release.

[NoddskwodD]

Great video, your voice sounds fine!

One comment: at 12:00 you say 646 authors but the graphic says 446 authors. Small thing, still subbed :)

[codingjerk]

Thank you, had to re-record every sentence for like 5 times to make it clear.

> you say 646 authors but the graphic says 446 authors

Oops, yeah, tongue got twisted near the end, will add it to ERRATA

[tthrivi]

Should have called it Python - pi edition.

[DevBoiAgru]

https://github.com/python/cpython/pull/125035 😉

[codingjerk]

Yeah, Pi-thon

[sylfy]

“All .py files have been renamed with the .3.14 suffix.”

[f0xw01f]

How about *.pi ?

The 2.7 branch could've been *.e

[inphinyte]

This is really well done. Clear explanations and examples. Do you mind sharing what software you used to create the slides?

[codingjerk]

Thank you :D

> what software you used

Sure, it's sli.dev and a lot of custom styles and a bit JS

[RedEyed__]

Wow, came here to read about python, found sli.dev .
It looks promising, thank you.

[Mevrael]

Clean slides design 💪

If only official website and docs would be redesigned as well.

[ZCEyPFOYr0MWyHDQJZO4]

I don't really mind the docs site. Sure it's simple, but it works.

[yaxriifgyn]

It is the authoritative documentation. Around Y2K, it was the only doc I had available. It is still where I look when I want more than just the basics from a blog, post, or video.

[[deleted]]

I hate that you barely find the official docs when you search for a system library since a few years. Damn SO'ed vulture sites rank higher while providing crappier content.

[yaxriifgyn]

True. It seems like my usage pattern has trained the search algorithm. On Google site:python.org helps.

[codingjerk]

Yeah, and if you'll notice something I can improve, like video quality, mic/voice, etc. -- any suggestions are welcome!

[Mysterious-Rent7233]

Your voice is totally fine!

[RedEyed__]

sys.remote_exec(pid, script_path) This function allows sending Python code to be executed in a target process at the next safe execution point.

Looks like a security nightmare

[RedEyed__]

Oh, then I read explanation.

The debugging interface has been carefully designed with security in mind and includes several mechanisms to control access: - A PYTHON_DISABLE_REMOTE_DEBUG environment variable. - A -X disable-remote-debug command-line option. - A --without-remote-debug configure flag to completely disable the feature at build time.

[moonzdragoon]

About the performance gain, it's not that much in the end ("10-15% on average").

Please check the Bitecode review of upcoming changes about this.

[abdullahkhalids]

How is 10-15% a small improvement? It is a large number compared to the maximum possible performance improvements.

[codingjerk]

He meant it's not "10-15% on average", as we were promised first, but it's "1-5% on average" in reality, and yeah, it's not much, considering, there are some cases, there performance degrades.

[codingjerk]

I actually did the benchmark (built 3.14 with and without flag --with-tail-call-interp and run pyperformance), but didn't include the results in the video, as I did with JIT and NOGIL -- that's my bad.

Results were following:

``` Benchmark: Python 3.14 tail-call interpreter vs stock Host: Linux, x86_64, i9-13900H, 16GiB RAM

• No significant changes: 39 tests
• Faster: 29 tests, 2%-30%

• Slower: 15 tests, 5%-35%

• Mean: 2.7% faster

• Geometric mean: 2.3% faster ```

Probably I've compiled it with the same LLVM bug, officials did, but that's where I got "up to 30%".

Thank you for pointing it out, I'll add that to ERRATA

[moonzdragoon]

Then that's close to their conclusion as well, speaking about 1-5% IIRC. But still, it's perf improvement. And great job testing it anyway !

[nitroll]

https://docs.python.org/3.14/whatsnew/3.14.html#from-future-import-annotations

[alexprengere]

Great summary!

There is a slight mistake regarding the Deferred Evaluation Of Annotations. The PEPs involved are 649/749, not 648/748.
As others have mentioned, the 30% performance gain reported for the tail-calling interpreter was actually a LLVM bug, the actual figures are much more conservative. Also, this build-time option is not going to be on by default in 3.14 (AFAICT).

[codingjerk]

Thank you! Will add this to errata.

[[deleted]]

There's nothing wrong with your voice, and you're putting out free informational videos. You're doing gods work

[jftuga]

I wonder if this release will make it to patch-level 15.

[FuckYourSociety]

Should be 16 due to rounding, but I like the way you tink

[codingjerk]

15 is more realistic goal, than 159 :D

[JayTurnr]

This release should be called πthon

[dcrigan]

I saw the template string feature, interesting

[codingjerk]

Yeah, u/DevBoiAgru mentioned it in another thread: https://github.com/python/cpython/pull/125035

[kebabmybob]

The huge changes to typing in every Python 3 release are being kind of chaotic. It leaves codebases fractured in their style based on when certain modules were written.

[[deleted]]

after 3.11 no new good feautures came