🌐 Mailman 3 July 2023 - Python-list - python.org

>>> %matplotlib inline results in SyntaxError: invalid syntax
by Mike S Dec. 25, 2023

Dec. 25, 2023

I have installed Python 3.4.4 on XPSP3 and am trying to work my way through this tutorial. A Complete Tutorial on Ridge and Lasso Regression in Python http://www.analyticsvidhya.com/blog/2016/01/complete-tutorial-ridge-lasso-r… In Step 2 "Why Penalize the Magnitude of Coefficients?" we are shown this code: #Importing libraries. The same will be used throughout the article. import numpy as np import pandas as pd import random import matplotlib.pyplot as plt %matplotlib inline I get an error on the last line. I am running this code in Idle Python 3.4.4 Shell... Python 3.4.4 (v3.4.4:737efcadf5a6, Dec 20 2015, 19:28:18) [MSC v.1600 32 bit (Intel)] on win32 Type "copyright", "credits" or "license()" for more information. >>> import numpy as np >>> import pandas as pd >>> import random >>> import matplotlib.pyplot as plt >>> %matplotlib inline SyntaxError: invalid syntax What am I doing wrong? Suggested reading? TIA, Mike

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Fallback for operator and other dunder methods
by Dom Grigonis July 26, 2023

July 26, 2023

To illustrate what I was trying to achieve: class A: def __init__(self, arr): self.arr = arr def __getattr__(self, name): arr_method = getattr(self.arr, name) def wrapper(*args, **kwargs): new_arr = arr_method(*args, **kwargs) return type(self)(new_arr) return wrapper a = A(np.ones((1, 1))) print(a.sum().arr) # 1 print(a + 1) # TypeError: unsupported operand type(s) for +: 'A' and 'int' Is there a way to achieve it without actually implementing operators? I have looked at Proxy objects, but they do not seem suited to achieve this. (e.g. wrapt) If there is no way to do this, wouldn’t it be sensible to have a new method, say ‘__getattrspecial__’? Either with ability to customise for which operators it is being called or not. —Nothing ever dies, just enters the state of deferred evaluation— Dg

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Odd types.get_original_bases() behavior for classes with generic bases but no type arguments
by Chris Bouchard July 25, 2023

July 25, 2023

(Apologies if this has already been discussed. I tried to search and didn't find anything relevant.) I was playing around with 3.12.0b4 this evening and noticed an odd (to me, at least) behavior with types.get_original_bases(). I hesitate to call it a bug because I think I understand *why* it's behaving this way—I'm just not sure it's desirable. >>> T = typing.TypeVar("T") >>> class FirstBase(typing.Generic[T]): ... pass ... >>> class SecondBase(typing.Generic[T]): ... pass ... >>> class First(FirstBase[int]): ... pass ... >>> class Second(SecondBase[int]): ... pass ... >>> class Example(First, Second): ... pass ... >>> types.get_original_bases(Example) (FirstBase[int],) >>> Example.__bases__ (First, Second) >>> types.get_original_bases(First) (FirstBase[int],) In other words, types.get_original_bases(Example) is returning the original base types for First, rather than its own. I believe this happens because __orig_bases__ is only set when one or more bases are not types. In this case both bases are types, so Example doesn't get its own __orig_bases__. Then when types.get_original_bases() tries to get __orig_bases__ with getattr(cls, "__orig_bases__") or something morally equivalent, it searches the MRO and finds __orig_bases__ on First. The same thing also happens if all the bases are "bare" generic types. >>> class First(typing.Generic[T]): ... pass ... >>> class Second(typing.Generic[T]): ... pass ... >>> class Example(First, Second): ... pass ... >>> types.get_original_bases(Example) (typing.Generic[~T],) As I said, I'm not clear if this is a bug, or just an unfortunate but intended behavior. I would personally expect types.get_original_bases() to check if the type has its *own* __orig_bases__ attribute, and to fall back to __bases__ otherwise. The way it works today makes it unnecessarily difficult to write a function that, for example, recurses down a type's inheritance tree inspecting the original bases—I currently have to work around this behavior via hacks like checking "__orig_bases__" in cls.__dict__ or any(types.get_original_bases(cls) == types.get_original_bases(base) for base in cls.__bases__). (Unless I'm missing some simpler solution.) Is this something that could (should?) be addressed before 3.12 lands? Thanks, Chris Bouchard

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pip-sync
by Larry Martell July 24, 2023

July 24, 2023

I am trying to set up and maintain a venv with pip-sync. On my bare metal I have the apparmor python package installed, but it is not installed in my venv and it's not in my requirements file. When I run pip-sync I get: Found existing installation: apparmor 2.13.3 ERROR: Cannot uninstall 'apparmor'. It is a distutils installed project and thus we cannot accurately determine which files belong to it which would lead to only a partial uninstall. Since it's not installed in the venv why does it want to uninstall it?

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Re: pip-sync
by Lars Liedtke July 24, 2023

July 24, 2023

This email contains a secure message that can be read by opening the attachment. Lars Liedtke Senior Software Developer [Tel.] [Fax] +49 721 98993- [E-Mail] lal(a)solute.de<mailto:lal@solute.de> solute gmbh Zeppelinstraße 15 76185 Karlsruhe Germany [Logo Solute] Marken der solute gmbh | brands of solute gmbh [Marken] Triff uns auf der DMEXCO am 20. und 21. September in Köln und sichere dir die Chance auf eine brandneue Apple-Watch bei unserer Live-Auslosung! Vereinbare hier einen Termin mit uns: https://outlook.office365.com/owa/calendar/solutedmexco@o365.solute.de/book… [dmexco Banner]<https://outlook.office365.com/owa/calendar/solutedmexco@o365.solute.de/book…> Geschäftsführer | Managing Director: Dr. Thilo Gans, Bernd Vermaaten Webseite | www.solute.de <http://www.solute.de/> Sitz | Registered Office: Karlsruhe Registergericht | Register Court: Amtsgericht Mannheim Registernummer | Register No.: HRB 110579 USt-ID | VAT ID: DE234663798 Informationen zum Datenschutz | Information about privacy policy https://www.solute.de/ger/datenschutz/grundsaetze-der-datenverarbeitung.php

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Meta Class Maybe?
by Chris Nyland July 22, 2023

July 22, 2023

So I am stuck on a problem. I have a class which I want to use to create another class without having to go through the boiler plate of subclassing. Specifically because the subclass needs to have certain class attributes and I would like to control how those are passed to provide defaults and such. What I have working right now is class Foo(): @classmethod def method_a(cls): print(cls.name) Bar = type('Bar', (Foo,), {'name': 'test1'}) Bar.method_a() This is sort of fine but the user needs to know how to call type and include all the base classes etc. I could just wrap the type call in a function like below def BarMaker(name): return type('Bar', (Foo,), {'name': name}) But then if the user needs to actually subclass Foo, to add additional methods that is more difficult. Of course those methods could be added as part of the third argument to types but that just doesn't feel very Python. This is all complicated by the fact that I am trying to avoid actually instancating any of these classes because their purpose is to be passed off to another framework to be executed. In real life most of the classes would fail to instantiate because they are relying on pieces of the framework that won't be up and running when this setup is happening. The solution I am hoping for is something like Foo(name, **kwds) -> Returns new class type of name For example test = Foo('test') So that then optionally a user could do class UserClass(Foo): def new_method(): pass bar = UserClass('Bar') Or something similar. Since I have a working example with type I feel like there should be a way to do this with the normal class structure but I am at a loss for how I have messed with the __new__ and __prepare__ methods and I can't seem to make anything work and the examples of meta classes don't clearly show how to convert my type example to a class structure. Is what I want to do possible? Chris

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ANN: A new version (0.5.1) of python-gnupg has been released.
by Vinay Sajip July 22, 2023

July 22, 2023

What Changed? ============= This is an enhancement and bug-fix release, and all users are encouraged to upgrade. Brief summary: * Added TRUST_EXPIRED to trust_keys. * Fix #206: Remove deprecated --always-trust in favour of --trust-model always * Fix #208: Add status_detail attribute to result objects which is populated when the status is 'invalid recipient' (encryption/decryption) or 'invalid signer' (signing). This attribute will be set when the result object's status attribute is set to 'invalid recipient' and will contain more information about the failure in the form of reason:ident where reason is a text description of the reason, and ident identifies the recipient key. * Add scan_keys_mem() function to scan keys in a string. * Fix #214: Handle multiple signatures when one of them is invalid or unverified. * A problems attribute was added which holds problems reported by gpg during verification. This is a list of dictionaries, one for each reported problem. Each dictionary will have status and keyid keys indicating the problem and the corresponding key; other information in the dictionaries will be error specific. * Fix #217: Use machine-readable interface to query the gpg version. * Added the ability to export keys to a file. This release [2] has been signed with my code signing key: Vinay Sajip (CODE SIGNING KEY) <vinay_sajip at yahoo.co.uk> Fingerprint: CA74 9061 914E AC13 8E66 EADB 9147 B477 339A 9B86 Recent changes to PyPI don't show the GPG signature with the download links. An alternative download source where the signatures are available is at [4]. The source code repository is at [1]. Documentation is available at [5]. As always, your feedback is most welcome (especially bug reports [3], patches and suggestions for improvement, or any other points via this group). Enjoy! Cheers Vinay Sajip [1] https://github.com/vsajip/python-gnupg [2] https://pypi.org/project/python-gnupg/0.5.1 [3] https://github.com/vsajip/python-gnupg/issues [4] https://github.com/vsajip/python-gnupg/releases/ [5] https://docs.red-dove.com/python-gnupg/

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Announcement: distlib 0.3.7 released on PyPI
by Vinay Sajip July 17, 2023

July 17, 2023

Version 0.3.7 of distlib has recently been released on PyPI [1]. For newcomers, distlib is a library of packaging functionality which is intended to be usable as the basis for third-party packaging tools. The main changes in this release are as follows: * Handle bare newlines when parsing metadata. * Use version comparison logic for python_full_version. * Fix shebang computation for source builds of Python. * Extract tarfiles more safely by incorporating tarfile filters. * Check for 'has_cert' attribute before using it. * Fix #200: Improve conformance to PEP440. * Fix #203: Handle parsing of export entries to allow script names such as "," or ",foo". A more detailed change log is available at [2]. Please try it out, and if you find any problems or have any suggestions for improvements, please give some feedback using the issue tracker at [3]. Regards, Vinay Sajip [1] https://pypi.org/project/distlib/0.3.7/ [2] https://distlib.readthedocs.io/en/0.3.7/overview.html#change-log-for-distlib [3] https://github.com/pypa/distlib/issues/new/choose

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Working with paths
by Peter Slížik July 16, 2023

July 16, 2023

Hello, I finally had a look at the pathlib module. (Should have done it long ago, but anyway...). Having in mind the replies from my older thread (File system path annotations), what is the best way to support all possible path types? def doit(path: str | bytes | os.PathLike): match path: case str() as path: print("string") case bytes() as path: print("bytes") case os.PathLike() as path: print("os.PathLike") Should I branch on the individual types or is there a more elegant way? Peter

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Setup-tools
by YOUSEF EZZAT July 16, 2023

July 16, 2023

Hey!..... i face a problem when i get setup packages by pip when i code this : "pip install numpy" in my command line it gives me error "ModuleNotFoundError: No module named 'distutils' " please, i need help for solving this problem......... i have python 3.12.0b4

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