Mailman 3 - Python-Dev

IMPORTANT: Check the 3.11.0 cherry-picks
by Pablo Galindo Salgado Oct. 24, 2022

Oct. 24, 2022

Hi everyone, I emerged from cherry-picking hell! As mentioned previously, the 3.11.0 final release will be done from the "branch-v3.11.0" branch and will contain a bunch of cherry-picked commits on top of v3.11.0rc2. These commits are: * All documentation commits that **do not touch** any source code (120+ commits). * The following bugfixes: + 6b999982cb8 gh-95027: Fix regrtest stdout encoding on Windows (GH-98492) + 970c10aa6d0 gh-97616: list_resize() checks for integer overflow (GH-97617) +… [View More]

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RELEASE MANAGEMENT: Python 3.11 release stream
by Pablo Galindo Salgado Oct. 22, 2022

Oct. 22, 2022

Hi everyone, I am currently swamped fixing merge conflicts from the cherry-picking to the final release candidate but I wanted to write to tell you I'm excited to confirm that we will be haven a Python 3.11 release party as we did last year with 3.10. The event will be co-hosted by the fantastic people of the Python discord channel. The URL for the stream is this one: https://www.youtube.com/watch?v=PGZPSWZSkJI *The release party will start on October 24th at 17:00 UTC+0.* In this stream, … [View More]

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How about using modern C++ in development of CPython ?
by redradist＠gmail.com Oct. 19, 2022

Oct. 19, 2022

Hi all, What about of using modern C++ in developing CPython ? With C++ we can get the following benefits: 1) Readability - less code, most code is hidden by abstraction without losing performance 2) Maintainability - no code duplication in favor of using reusable classes 3) RAII - Resource Acquisition Is Initialization, predictable allocation and free resources ...

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[RELEASE] Python versions 3.10.8, 3.9.15, 3.8.15, 3.7.15 now available
by Łukasz Langa Oct. 11, 2022

Oct. 11, 2022

Déjà vu? Right, a month after the expedited releases we are doing the dance again. This coincides with the regular scheduled time for 3.10.8 but since we accrued a few fixes in 3.7 - 3.9 as well, we’re again releasing all four editions at the same time. We’re not promising to continue at this pace 😅 <https://discuss.python.org/t/python-versions-3-10-8-3-9-15-3-8-15-3-7-15-no…>Security content this time CVE-2022-40674: bundled libexpat was upgraded from 2.4.7 to 2.4.9 which fixes a … [View More]heap use-after-free vulnerability in function doContent gh-97616: a fix for a possible buffer overflow in list *= int gh-97612: a fix for possible shell injection in the example script get-remote-certificate.py (this issue originally had a CVE assigned to it, which its author withdrew) gh-96577: a fix for a potential buffer overrun in msilib <https://discuss.python.org/t/python-versions-3-10-8-3-9-15-3-8-15-3-7-15-no…>Python 3.10.8 Get it here: https://www.python.org/downloads/release/python-3108/ <https://www.python.org/downloads/release/python-3108/> As a bugfix release coming a mere month after an out-of-schedule security release, 3.10.8 is somewhat smaller compared to 3.9.8 released at the same stage of the release cycle a year ago. There’s 151 commits vs 204 in 3.9. It’s still a larger release than 3.10.7 at 113 commits. One way or the other, it’s worth checking out the change log <https://docs.python.org/release/3.10.8/whatsnew/changelog.html>. <https://discuss.python.org/t/python-versions-3-10-8-3-9-15-3-8-15-3-7-15-no…>And now for something completely different Granular convection is a phenomenon where granular material subjected to shaking or vibration will exhibit circulation patterns similar to types of fluid convection. It is sometimes described as the Brazil nut effect when the largest particles end up on the surface of a granular material containing a mixture of variously sized objects; this derives from the example of a typical container of mixed nuts, where the largest will be Brazil nuts. The phenomenon is also known as the muesli effect since it is seen in packets of breakfast cereal containing particles of different sizes but similar densities, such as muesli mix. Under experimental conditions, granular convection of variously sized particles has been observed forming convection cells similar to fluid motion. <https://discuss.python.org/t/python-versions-3-10-8-3-9-15-3-8-15-3-7-15-no…>We hope you enjoy the new releases! Thanks to all of the many volunteers who help make Python Development and these releases possible! Please consider supporting our efforts by volunteering yourself or through organization contributions to the Python Software Foundation. Your friendly release team, Ned Deily @nad <https://discuss.python.org/u/nad> Steve Dower @steve.dower <https://discuss.python.org/u/steve.dower> Pablo Galindo Salgado @pablogsal <https://discuss.python.org/u/pablogsal> Łukasz Langa @ambv <https://discuss.python.org/u/ambv> [View Less]

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Embedded Python Memory Leaks
by alexei73＠hotmail.com Oct. 8, 2022

Oct. 8, 2022

Hi Python team Is any plan to try and fix memory leaks when embedding Python in a C/C++ application? Thanks in advance, Alexei

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PEP 699: Remove private dict version field added in PEP 509
by Ken Jin Oct. 5, 2022

Oct. 5, 2022

I've created a new PEP to repeal PEP 509. Please post comments to the Discourse thread. Thank you! Discourse thread: https://discuss.python.org/t/pep-699-remove-private-dict-version-field-adde… Link to the PEP: https://github.com/python/peps/blob/main/pep-0699.rst

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Moving to Discourse
by Petr Viktorin Sept. 23, 2022

Sept. 23, 2022

As mentioned previously [0], the Steering Council decided to switch from python-dev to Discourse (discuss.python.org). We're aware that Discourse is not perfect. The previous mail thread [0] lists various shortcomings, as well as some workarounds. However, we don't see anything that would block Python development. Practically, the switch means that: - New PEPs should be announced in the PEPs category on Discourse (rather than on this list), and - The Devguide will list Discourse, rather … [View More]

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PEP 505 (None-aware operators) for Python 3.11
by Doug Swarin Sept. 21, 2022

Sept. 21, 2022

Hello, I've been following PEP 505 (https://www.python.org/dev/peps/pep-0505/) since it was first proposed for Python 3.8. It's been deferred for some time and I'm interested in seeing it in Python 3.11, but I know there were also a number of objections which resulted in it being deferred (including by one of the original authors, Mr. Dower). I did email both Mr. Dower and Mr. Haase and they graciously gave me their permission to bring it up on this list for discussion and hopefully final … [View More]

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Annotating pure functions to improve inline caching/optimization
by Philipp Burch Sept. 19, 2022

Sept. 19, 2022

Hello everyone, the docs on the upcoming 3.11 release state > This [specializing adaptive interpreter] also brings in another concept called inline caching, where Python caches the results of expensive operations directly in the bytecode. I wonder how this caching works, given that the dynamic nature means that virtually every operation could have side effects, causing wrong behaviour when cached. The only mitigation for this that I can imagine is that caching just occurs for basic … [View More]operations defined in the standard library, where it is known that they are free of side effects or "pure". A web search did reveal some discussions[1,2] and a module related to dealing with pure functions, but, as far as I see, not related to optimization. As an example, consider a code like this: ```py @pure def rot_factor(angle_deg: float) -> complex: # This could also be a much more expensive calculation. return cmath.exp(angle_deg / 180 * cmath.pi * 1j) # ... res: List[Tuple(complex, complex, complex, float)] = [] for x in many: res.append(( x * rot_factor(90), x * rot_factor(45), x * rot_factor(-45), x * math.sin(math.pi/8), )) ``` The problem with this code is obvious, every loop iteration calls `rot_factor()` with 90, 45 and -45 and will get exactly the same set of results. The last factor might already be inline cached by the interpreter, since it probably knows that `math.pi` is a constant and `math.sin()` is a pure function. Optimizing this by hand (not considering a list comprehension or other more sophisticated improvements) is easy, but not very pretty: ```py f_p90 = rot_factor(90) f_p45 = rot_factor(45) f_m45 = rot_factor(-45) f_sin = math.sin(math.pi / 8) res: List[Tuple(complex, complex, complex, float)] = [] for x in many: res.append(( x * f_p90, x * f_p45, x * f_m45, x * f_sin, )) ``` I actually find myself often factoring such data out of loops in Python, whereas in C I would just leave that to the optimizer/compiler. An available option would be to use `@lru_cache` for `rot_factor()`, but this will still cause the same dictionary lookups in every iteration and it may not work at all in case the function argument(s) is/are not hashable. Now, if the interpreter understood the `@pure` decorator for `rot_factor()` indicated above would give it the same opportunity to cache the three results throughout the loop, basically creating the manually-optimized code above. For these completely static values, it could even precompute the results and integrate them into the bytecode. Has anything like this been considered already, or is the interpreter itself capable to perform such optimizations? Thanks and best regards, Philipp [1] 'pure' type annotation for mypy: https://github.com/python/mypy/issues/4468 [2] pure-func module: https://pypi.org/project/pure-func/ [View Less]

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glob's new include_hidden parameter
by Mats Wichmann Sept. 13, 2022

Sept. 13, 2022

Just spotted that 3.11 adds an include_hidden. At the moment a little confused because there's an apparent mismatch between docstring and docs. Lib/glob.py: If `include_hidden` is true, the patterns '*', '?', '**' will match hidden directories. Doc/library/glob.rst: If *include_hidden* is true, "``**``" pattern will match hidden directories. ,,, with no mention of the other patterns. Is that just an omission in the rst doc?

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