Mailman 3 September 2021 - Python-Dev

Porting python.gram to Python
by Erik Demaine Sept. 23, 2021

Sept. 23, 2021

Dear python-dev, I've been working on a port of cpython/Grammar/python.gram from C (as currently used in all the {} expressions to build the AST) to Python, directly building nodes via the ast package. My motivation for this (as opposed to calling ast.parse, which uses the C parser) is to make it easy to experiment with adding features to the syntax, without having to build CPython. Porting is mostly straightforward, but it is a fair amount of work, because there are a lot of … [View More]

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July Steering Council update.
by Thomas Wouters Sept. 23, 2021

Sept. 23, 2021

FYI, I've just published the July steering council update, also included below: https://github.com/python/steering-council/blob/main/updates/2021-07-steeri… Just as a reminder, if you have any questions or concerns, feel free to contact us or open an issue in the SC repo: https://github.com/python/steering-council July 5 - No regular meeting because of the US holiday. - Most of the Steering Council met with Nathaniel Smith to discuss his alternative proposal for PEP 654 <… [View More]https://www.python.org/dev/peps/pep-0654/> (Exception Groups and except *). - Nathaniel and Carol will work to flesh out his proposal. <https://github.com/python/steering-council/blob/main/updates/2021-07-steeri…>July 12 - Steering Council discussed a clarification request from the PyPA folks around PEPs. It was determined that PyPA folks can sponsor their own PEPs. Brett informed them by responding to the comment. - SC discussed the enum repr() and str() changes in 3.10 and 3.11. - SC discussed PEP 582 <https://www.python.org/dev/peps/pep-0582/> (Python local packages directory). <https://github.com/python/steering-council/blob/main/updates/2021-07-steeri…>July 19 - Steering Council met with Łukasz, the Developer-in-Residence for the first time. The group discussed prioritization, balancing, and how to handle group requests. The Steering Council needs to handle prioritization if folks send Łukasz their lists of jobs. The group also discussed how this role is going to impact the strategic approach of merging issues from bugs.python.org to GitHub. A group Slack channel was created for Łukasz to have a way to ping the SC outside of email. The SC and Łukasz will meet every two weeks for now. - Group discussed PEP 649 <https://www.python.org/dev/peps/pep-0649/> (Deferred Evaluation Of Annotations Using Descriptors) and typing in general. The group determined that they need to discuss the status of typing as part of the language, and write up a PEP to the community so the community knows how to proceed with typing PEPs. - Steering Council will continue to review PEP 648 <https://www.python.org/dev/peps/pep-0648/> (Extensible customizations of the interpreter at startup) and will discuss it via email. <https://github.com/python/steering-council/blob/main/updates/2021-07-steeri…>July 26 - The Steering Council discussed PEP 648 <https://www.python.org/dev/peps/pep-0648/> (Extensible customizations of the interpreter at startup) and decided the PEP needed more use cases and feedback from the community. The group is going to draft a response (reject it and tell them use cases are needed) and Barry will send it. If the PEP author provides use cases the SC can revisit the PEP later. - The SC discussed PEP 467 <https://www.python.org/dev/peps/pep-0467/> (Minor API improvements for binary sequences) and decided that they will recommend removing the bchr builtin from the PEP and then the SC can review the revised PEP if the author wants to revisit it. - Thomas created the private Python committers Discord and Pablo suggested we use it for the next virtual Sprint, which the group agrees with. -- Thomas Wouters <thomas(a)python.org> Hi! I'm an email virus! Think twice before sending your email to help me spread! [View Less]

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Re: f-strings in the grammar
by Anders Munch Sept. 21, 2021

Sept. 21, 2021

Pablo Galindo Salgado [mailto:pablogsal@gmail.com] wrote: > We already expose APIs that return AST objects that can be used for all sort of things and a tokenizer module that exposes some form of lexing that is relatively close to the one that CPython uses internally. What do you envision tokenize.py will do with f-strings after this? What would be the output of, say, $ echo 'f"hello {world!r}."' | python3 -m tokenize ? regards, Anders

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Re: f-strings in the grammar
by Patrick Reader Sept. 21, 2021

Sept. 21, 2021

I didn't meant to bring back backticks, but to use the semantics they have in shell languages of using backslashes to escape nested substitutions, like this: f"string {code f\"string2 \{code2\} string2\" code} string" Upon reflection though, I agree that since we already use brackets which lend themselves to nesting, it probably does make more sense to use them for nesting. On 20/09/2021 21:25, Guido van Rossum wrote: > On Mon, Sep 20, 2021 at 1:07 PM Patrick Reader <_(a)pxeger.com … [View More]

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Regressions caused the recent work on ceval.c and frame objects
by Victor Stinner Sept. 20, 2021

Sept. 20, 2021

Hi, The recent optimization work on ceval.c and frame objects introduced regressions and the situation is stuck for 4 months (bpo-43760). Right now, maybe the best would be to revert the 2 commits in the 3.10 branch, to get more time in Python 3.11 development cycle to solve these issues. (1) "The DISPATCH() macro is not as efficient as it could be (move PyThreadState.use_tracing)" https://bugs.python.org/issue43760 This change introduced an incompatible C API change. It's not documented … [View More]

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Summary of Python tracker Issues
by Python tracker Sept. 17, 2021

Sept. 17, 2021

ACTIVITY SUMMARY (2021-09-10 - 2021-09-17) Python tracker at https://bugs.python.org/ To view or respond to any of the issues listed below, click on the issue. Do NOT respond to this message. Issues counts and deltas: open 7381 ( +5) closed 49587 (+63) total 56968 (+68) Open issues with patches: 2938 Issues opened (37) ================== #45170: tarfile missing cross-directory checking https://bugs.python.org/issue45170 opened by xiongpanju #45171: stacklevel handling in … [View More]

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What's the rule for issuing line tracing numbers when using a tracing function?
by Fabio Zadrozny Sept. 17, 2021

Sept. 17, 2021

Hi all, I have a weird case where I thought line events would be issued and yet they aren't even though they're in the instructions in the bytecode (both in 3.9 and 3.10). i.e.: Given the code: def check_backtrack(x): # line 1 if not (x == 'a' # line 2 or x == 'c'): # line 3 pass # line 4 it has dis.dis such as: 2 0 LOAD_FAST 0 (x) 2 LOAD_CONST 1 ('a') 4 COMPARE_OP 2 (==) … [View More]

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python3.10rc2 compilation on android/termux/clang12.0.1 fails
by Sandeep Gupta Sept. 17, 2021

Sept. 17, 2021

I am trying to compile Python3.10rc2 on rather unusual platform (termux on android). The gcc version is listed below: ~ $ g++ -v clang version 12.0.1 Target: aarch64-unknown-linux-android24 Thread model: posix InstalledDir: /data/data/com.termux/files/usr/bin I get following warnings and errors: Python/pytime.c:398:10: warning: implicit conversion from 'long' to 'double' changes value from 9223372036854775807 to 9223372036854775808 [-Wimplicit-const-int-float-conver sion] if (!… [View More]

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Discussion about how to manage additions/removals to the stdlib
by Brett Cannon Sept. 16, 2021

Sept. 16, 2021

https://discuss.python.org/t/how-do-we-want-to-manage-additions-removals-to… This comes from my language summit talk on the stdlib to help clarify some things about how we manage the stdlib from the perspective of additions/deletions. FYI I will be *muting this email thread immediately*, so please participate on discuss.python.org if you have anything to say (I almost didn't post here, but I figured I would see if there's any chance people will follow through on discuss.python.org if directed … [View More]

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How to decipher Windows errors on builds?
by Mark Shannon Sept. 16, 2021

Sept. 16, 2021

Hi, I'm getting build errors on Windows for https://github.com/python/cpython/pull/28386 The error message is: C:\Program Files (x86)\Windows Kits\10\Include\10.0.22000.0\um\winnt.h(253): error RC2188: D:\a\cpython\cpython\PCbuild\obj\311win32_Release\pythoncore\RCa01688(47) : fatal error RC1116: RC terminating after preprocessor errors [D:\a\cpython\cpython\PCbuild\pythoncore.vcxproj] Can anyone translate that into English for me? It suggests that there are errors in the preprocessor.… [View More]

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