Unlocking Python's Potential: The Dawn of Free-Threaded CPython

The recent release of CPython 3.14.0b1 marks a pivotal moment in Python's evolution, introducing free-threaded capabilities that promise to unleash the full power of modern multicore architectures. Th...

https://news.lavx.hu/article/unlocking-python-s-potential-the-dawn-of-free-threaded-cpython

Trying to gather feedback/opinions, especially from #CPython Core Developers, on the recent #fuzzing campaign using #fusil.

https://discuss.python.org/t/feedback-on-the-recent-fusil-fuzzing-campaign-of-cpython/91737

I'm writing a little tech report on the effort, and having some data about whether it's considered useful, a nuisance, impactful, low value etc. would make it much more interesting.

Please boost for visibility :)

Another tidbit from the report I'm writing about #fusil:

The 52 issues filled correspond roughly to 30% of all the crashes (issues with "type-crash" label) and 2% of all issues (features requests, bugs and invalid issues) reported in the #CPython issue tracker during the six months period covered by the report.

Hits and new issues don't appear at a steady pace. It seems that there are long periods of no or nearly no new issues, followed by rapid finding of new results.

@ambv Hi! Couldn't help but notice that #cpython isn't in the list of dev sprints happening this year at Pycon.

Will you folks be sprinting? :) No worries in any case, just trying to make a stab at a plan for my sprint days :)

Writing about #fusil. Some bits:

Fuzzing #CPython with fusil shows it to be a valuable tool for finding and fixing crashers. It started in October 2024 and is ongoing, using free tier cloud instances and personal computers.

Results:
- Fuzzing time: > 25.000 hours
- Fuzzing sessions: > 1.000.000
- Hits: > 50.000
- Issues filled: 52

The original design of fusil makes it well-suited for fuzzing CPython, finding both deep, relevant bugs as well as shallow, low value crashes.

Very busy day at the #CPython repository as tomorrow's feature freeze for the first beta of version 3.14 approaches: https://github.com/python/cpython/issues?q=sort%3Aupdated-desc

Tons of neat features and improvements landing today.

We all know the number of stars on GitHub is an excellent metric for understanding how many people has starred a repo.

CPython now has 66.6k stars

❯ gh repo view python/cpython --json stargazerCount
{
"stargazerCount": 66645
}

Can exactly 21 people, and no more, star it to get to 66666?

https://github.com/python/cpython/

#Python #CPython #GitHub #stargazers #

all tests passing for system
yet to integrate & test multiple more things and dump that to ci/cd pipeline
hmm what kind of work is that.
why is #cpython so prominently used for this?
-- noob

Do you maintain or contribute to a #Python package that includes a C extension? Would you like to run a fuzzer against it?

If so, let me know and I will run it, or help you to get it running.

The fuzzer is #fusil, which generates random code calling into your functions and methods. It's useful to check for crashes on invalid inputs or unexpected call patterns.

It has found about 50 crashes in #CPython, 20 in #PyPy, 6 in #Numpy etc.

#fuzzing #fuzzer #testing
See here:
https://github.com/devdanzin/fusil/issues/37

Yesterday someone reported that the recursion limit isn't fully enforced in Python 3.13: https://discuss.python.org/t/infinite-recursion/88900

Today I accidentally discovered a segmentation fault introduced in Python 3.12: https://github.com/python/cpython/issues/132747

What a weekend.

Сворачиваем CPython вокруг PVS-Studio

Python... язык программирования, не нуждающийся в особом представлении. За удобство в обработке "больших данных" заслуженно получил звание "лучшего Excel". За удобство интеграции в C и C++ код его любит геймдев. А также у него низкий порог вхождения! Но как обстоят дела внутри?

https://habr.com/ru/companies/pvs-studio/articles/902048/

О чем на этот раз будет Python Day на Positive Hack Days

24 мая в рамках

https://habr.com/ru/companies/pt/articles/901568/

Sending a big thank you to Arm for providing ARM GitHub Action runners to CPython ahead of the public preview launch today! https://github.blog/changelog/2025-04-14-windows-arm64-hosted-runners-now-available-in-public-preview/ #python #cpython
https://github.blog/changelog/2025-04-14-windows-arm64-hosted-runners-now-available-in-public-preview/

Unlocking Python Performance: The Surprising Speed of 'if not mylist' Over 'len(mylist) == 0'

In the world of Python development, performance can often hinge on seemingly minor syntactic choices. A deep dive into CPython's internals reveals that using 'if not mylist' can be nearly twice as fas...

https://news.lavx.hu/article/unlocking-python-performance-the-surprising-speed-of-if-not-mylist-over-len-mylist-0

Как я стал core-разработчиком Python в 19 лет

Как я стал core-разработчиком CPython в 19 лет: История усилий и достижений В этой статье я расскажу, сколько усилий потребовалось, чтобы стать частью команды разработчиков CPython и какие возможности это открыло для меня.

https://habr.com/ru/articles/899636/