🌐 Mailman 3 March 2024 - Python-list - python.org

[Ann] managesieve v0.8 released
by Hartmut Goebel March 18, 2024

March 18, 2024

Announcing: managesieve 0.8 RFC-5804 Manage Sieve client library for remotely managing Sieve scripts, including an user application (the interactive 'sieveshell'). :Homepage: https://managesieve.readthedocs.io/ :Author: Hartmut Goebel <h.goebel(a)crazy-compilers.com> :License: - for the managesieve module: Python-Software-Foundation-like License - for sieveshell and test suite: GNU Public Licence v3 (GPLv3) :Quick Installation: pip install -U managesieve :Tarballs: https://pypi.org/project/managesieve/#files What is managesieve? --------------------- A ManageSieve client library for remotely managing Sieve scripts, including an user application (the interactive 'sieveshell'). Sieve scripts allow users to filter incoming email on the mail server and are supported by many IMAP servers. The ManageSieve protocol allows managing Sieve scripts on a remote mail server. These servers are commonly sealed so users cannot log into them, yet users must be able to update their scripts on them. This is what for the "ManageSieve" protocol is. For more information about the ManageSieve protocol see `RFC 5804 <http://tools.ietf.org/html/rfc5804>`_. This module allows accessing a Sieve-Server for managing Sieve scripts there. It is accompanied by a simple yet functional user application 'sieveshell'. Changes since last release --------------------------------------- * Now supports Python 3.6 to 3.12. :managesieve: - Add support for the UNAUTHENTICATE command. - Add a socket timeout parameter. - Add support for IPv6. - Allow disabling certificate verification. - Follow the 'Logging for a Library' guideline. - BREAKING: Rearrange DEBUG logging levels to be more reasonable. See `docs/Logging.rst` for details. :sieveshell: - Add option '--no-tls-verify'. - Improve error message if TLS certificate verification fails. - Keep line-endings on file IO. - Remove temporary file on successful edit, too. - Fix: Pass to sieve.login() the Authorization ID :general: - Add support for Python 3.12. - Improve testing, add a tox.ini file and add CI/CD. - Fix SPDX license identifier. - Fix several typos. - Lint all the code. - Remove unused code. -- Regards Hartmut Goebel | Hartmut Goebel | h.goebel(a)crazy-compilers.com | | www.crazy-compilers.com | compilers which you thought are impossible |

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MTG: Introductions to PyQt and DataClasses
by dn March 17, 2024

March 17, 2024

The Auckland Branch of NZPUG meets this Wednesday, 20 March at 1830 NZDT (0530 UTC, midnight-ish Tue/Wed in American time-zones), for a virtual meeting. Part 1: Learn the basics of PyQt with code examples. Hannan Khan is currently consulting as a Data Scientist for the (US) National Oceanic and Atmospheric Administration. He holds a Bachelor's degree in Neuroscience as well as a Masters in Computer Science. As a keen member of the PySprings Users' Group (Colorado), his contribution is part of a collaboration between our two PUGs. Part 2: Why use Dataclasses? - will be the question asked, and answered, by yours truly. After surveying a number of groups, it seems most of us know that Dataclasses are available, but we don't use them - mostly because we haven't ascertained their place in our tool-box. By the end of this session you will, and will have good reason to use (or not) Dataclasses! Everyone is welcome from every location and any time-zone. The NZPUG Code of Conduct applies. JetBrains have kindly donated a door-prize. Our BigBlueButton web-conferencing instance is best accessed using Chromium, Brave, Vivaldi, Safari, etc, (rather than Firefox - for now). A head-set will facilitate asking questions but text-chat will be available. Please RSVP at https://www.meetup.com/nzpug-auckland/events/299764049/ See you there! =dn, Branch Leader

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[RELEASE] Python 3.13.0a5 is now available
by Thomas Wouters March 12, 2024

March 12, 2024

We’re getting closer and closer… Alpha 5 is here. https://www.python.org/downloads/release/python-3130a5/ *This is an early developer preview of Python 3.13* Major new features of the 3.13 series, compared to 3.12 Python 3.13 is still in development. This release, 3.13.0a5, is the fifth of six planned alpha releases. Alpha releases are intended to make it easier to test the current state of new features and bug fixes and to test the release process. During the alpha phase, features may be added up until the start of the beta phase (2024-05-07) and, if necessary, may be modified or deleted up until the release candidate phase (2024-07-30). Please keep in mind that this is a preview release and its use is *not* recommended for production environments. Many new features for Python 3.13 are still being planned and written. Work continues apace on both the work to remove the Global Interpeter Lock <https://peps.python.org/pep-0703/>, and to improve Python performance. The most notable changes so far: - In the interactive interpreter, exception tracebacks are now colorized by default <https://docs.python.org/dev/whatsnew/3.13.html#improved-error-messages>. - A preliminary, *experimental* JIT was added <https://docs.python.org/dev/whatsnew/3.13.html#experimental-jit-compiler>, providing the ground work for significant performance improvements. - Docstrings now have their leading indentation stripped <https://docs.python.org/dev/whatsnew/3.13.html#other-language-changes>, reducing memory use and the size of .pyc files. (Most tools handling docstrings already strip leading indentation.) - The dbm module <https://docs.python.org/dev/library/dbm.html> has a new dbm.sqlite3 backend <https://docs.python.org/dev/whatsnew/3.13.html#id1> that is used by default when creating new files. - PEP 594 (Removing dead batteries from the standard library) <https://peps.python.org/pep-0594/> scheduled removals of many deprecated modules: aifc, audioop, chunk, cgi, cgitb, crypt, imghdr, mailcap, msilib, nis, nntplib, ossaudiodev, pipes, sndhdr, spwd, sunau, telnetlib, uu, xdrlib, lib2to3. - Many other removals <https://docs.python.org/dev/whatsnew/3.13.html#removed> of deprecated classes, functions and methods in various standard library modules. - New deprecations <https://docs.python.org/dev/whatsnew/3.13.html#deprecated>, most of which are scheduled for removal from Python 3.15 or 3.16. - C API removals <https://docs.python.org/dev/whatsnew/3.13.html#id10> and deprecations <https://docs.python.org/dev/whatsnew/3.13.html#id9>. (Some removals present in alpha 1 have been reverted in alpha 2, as the removals were deemed too disruptive at this time.) (Hey, *fellow core developer,* if a feature you find important is missing from this list, let Thomas know <thomas(a)python.org>.) The next pre-release of Python 3.13 will be 3.13.0a6, currently scheduled for 2024-04-09. <https://discuss.python.org/t/python-3-13-0-alpha-5/48341#more-resources-2>More resources - Online Documentation <https://docs.python.org/3.13/> - PEP 719 <https://www.python.org/dev/peps/pep-0719/>, 3.13 Release Schedule - Report bugs at Issues · python/cpython · GitHub <https://github.com/python/cpython/issues>. - Help fund Python directly <https://www.python.org/psf/donations/python-dev/> (or via GitHub Sponsors <https://github.com/sponsors/python>), and support the Python community <https://www.python.org/psf/donations/>. <https://discuss.python.org/t/python-3-13-0-alpha-5/48341#enjoy-the-new-rele…>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. Regards from wet and chilly Amsterdam, Your release team, Thomas Wouters Ned Deily Steve Dower Łukasz Langa -- Thomas Wouters <thomas(a)python.org>

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A Single Instance of an Object?
by Ivan "Rambius" Ivanov March 11, 2024

March 11, 2024

Hello, I am refactoring some code and I would like to get rid of a global variable. Here is the outline: import subprocess CACHE = {} def lookup(key): """"Runs the command cmd, parses its output, extract's the key's value, caches it and returns it. If the key has already been in the cache, returns its cached value. If the command cmd returns an error, the value is set to None and cached as None.""" if key in CACHE: return CACHE[key] value = None cmd = f"mycmd {key}" proc = subprocess(cmd, capture_output=True, text=True, check=False) if proc.returncode == 0: value = proc.stdout.strip() else: logger.error("cmd returned error") CACHE[key] = value return value ... def main(): while True: keys = load_keys() for key in keys: call_function_that_call_function_that_calls_lookup(key) The global cache variable made unit testing of the lookup(key) method clumsy, because I have to clean it after each unit test. I refactored it as: class Lookup: def __init__(self): self.cache = {} def lookup(key): if key in self.cache: return self.cache[key] value = None cmd = f"mycmd {key}" proc = subprocess(cmd, capture_output=True, text=True, check=False) if proc.returncode == 0: value = proc.stdout.strip() else: logger.error("cmd returned error") self.cache[key] = value return value Now it is easier to unit test, and the cache is not global. However, I cannot instantiate Lookup inside the while- or for- loops in main(), because the cache should be only one. I need to ensure there is only one instance of Lookup - this is why I made it a global variable, so that it is accessible to all functions in that script and the one that actually needs it is 4 levels down in the call stack. I have never done that in Python because I deliberately avoided such complicated situations up to now. I know about the Singleton pattern, but I have never implemented it in Python and I don't know if it is Pythonish. I am looking for the same behaviour as logging.getLogger(name). logging.getLogger("myname") will always return the same object no matter where it is called as long as the name argument is the same. How would you advise me to implement that? Regards rambius -- Tangra Mega Rock: http://www.radiotangra.com

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Error in Module
by Sanskar Mukeshbhai Joshi March 11, 2024

March 11, 2024

Respected Sir/Ma'am I had made my project in BCA in Python. When I had complete my project and run the program, at that time I got the error in runnig my project. The error was ModuleNotFoundError: No module named 'flask'. I request you to check this problem and resolve it or guide me to solve this Error.

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pathlib.Path.is_file vs os.path.isfile difference
by Albert-Jan Roskam March 10, 2024

March 10, 2024

Hi, I was replacing some os.path stuff with Pathlib and I discovered this: Path(256 * "x").is_file() # OSError os.path.isfile(256 * "x") # bool Is this intended? Does pathlib try to resemble os.path as closely as possible? Best wishes, Albert-Jan

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Variable scope inside and outside functions - global statement being overridden by assignation unless preceded by reference
by Jacob Kruger March 8, 2024

March 8, 2024

Hi there Working with python 3.11, and, issue that confused me for a little while, trying to figure out what was occurring - unless am completely confused, or missing something - was that, for example, when having pre-defined a variable, and then included it in the global statement inside a function, that function was still referring to a completely local instance, without manipulating outside variable object at all unless I first executed a form of referral to it, before then possibly assigning a new value to it. Now, this does not seem to occur consistently if, for example, I just run bare-bones test code inside the python interpreter, but consistently occurs inside my actual testing script. Basically, in a file with python code in that am using for a form of testing at the moment, at the top of the file, under all the import statements, I initiate the existence of a list variable to make use of later: # code snippet l_servers = [] # end of first code snippet Then, lower down, inside a couple of different functions, the first line inside the functions includes the following: # code snippet global l_servers # end code snippet That should, in theory, mean that if I assign a value to that variable inside one of the functions, it should reflect globally? However, it seems like that, while inside those functions, it can be assigned a new list of values, but if I then return to the scope outside the functions, it has reverted back to being an empty list = []? The issue seems to specifically (or not) occur when I make a call to one function, and, in the steps it's executing in one context, while it's not doing anything to the list directly, it's then making a call to the second function, which is then meant to repopulate the list with a brand new set of values. Now, what almost seems to be occurring, is that while just manipulating the contents of a referenced variable is fine in this context, the moment I try to reassign it, that's where the issue is occurring . Here are relevant excerpts from the file:- # start code # original assignation in main part of file l_servers = [] # function wich is initially being executed def interact(): global l_servers # extra code inbetween choosing what to carry out # ... # end of other code bl_response, o_out = list_servers() if bl_response: # just make sure other function call was successful l_servers.clear() # first make reference to global variable for srv in o_out: l_servers.append(srv) # now re-populate items # end code snippet from inside interact function # end of interact function # end of code snippet That other function being called from within, list_servers() was initially just trying to populate the values inside the global list variable itself, but was ending up in a similar fashion - reverting to initial empty value, but, the above now seems to work, as long as I first make reference to/manipulate/work with global variable instead of just trying to reassign it a brand new value/set of items? So, am I missing something obvious, have I forgotten about something else - yes, know that if was working from within an embedded function, I might need/want to then use the nonlocal statement against that variable name, but, honestly, just not sure how this can be occurring, and, it's not just with this one list variable, etc.? If I try simple test code from within the python interpreter, using different types of variables, this does also not seem to be the same all the time, but, don't think it can relate to an iterable like a list, or else, just in case, here is the code snippet with all the import statements from the top of that file, in case something could be overriding standard behaviour - not likely in this context, but, really not sure what's occurring: # import code snippet import requests, time from requests.auth import HTTPBasicAuth import psutil as psu import pytz import bcrypt from copy import copy from datetime import datetime, timedelta, timezone from dateutil.parser import parse # end of import snippet Thanks if you have any ideas/thoughts on the matter Jacob Kruger +2782 413 4791 "Resistance is futile!...Acceptance is versatile..."

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If a dictionary key has a Python list as its value!
by Varuna Seneviratna March 7, 2024

March 7, 2024

If a dictionary key has a Python list as its value, you can read the values one by one in the list using a for-loop like in the following. d = {k: [1,2,3]} > for v in d[k]: > print(v) No tutorial describes this, why? What is the Python explanation for this behaviour? Varuna

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Can u help me?
by Chano Fucks March 6, 2024

March 6, 2024

[image: image.png]

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