🌐 Mailman 3 September 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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type annotation vs working code
by Karsten Hilbert Oct. 4, 2023

Oct. 4, 2023

A type annotation isn't supposed to change what code does, or so I thought: #------------------------------------------------------------ class Borg: _instances:dict = {} def __new__(cls, *args, **kargs): # look up subclass instance cache if Borg._instances.get(cls) is None: Borg._instances[cls] = object.__new__(cls) return Borg._instances[cls] class WorkingSingleton(Borg): def __init__(self): print(self.__class__.__name__, ':') try: self.already_initialized print('already initialized') return except AttributeError: print('initializing') self.already_initialized = True self.special_value = 42 class FailingSingleton(Borg): def __init__(self): print(self.__class__.__name__, ':') try: self.already_initialized:bool print('already initialized') return except AttributeError: print('initializing') self.already_initialized = True self.special_value = 42 s = WorkingSingleton() print(s.special_value) s = FailingSingleton() print(s.special_value) #------------------------------------------------------------ Notice how Working* and Failing differ in the type annotation of self.already_initialized only. Output: WorkingSingleton : initializing 42 FailingSingleton : already initialized <====================== Huh ? Traceback (most recent call last): File "/home/ncq/Projekte/gm/git/gnumed/gnumed/client/testing/test-singleton.py", line 48, in <module> print(s.special_value) ^^^^^^^^^^^^^^^ AttributeError: 'FailingSingleton' object has no attribute 'special_value' Where's the error in my thinking (or code) ? Thanks, Karsten -- GPG 40BE 5B0E C98E 1713 AFA6 5BC0 3BEA AC80 7D4F C89B

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Re: Dynamically modifying "__setattr__"
by Greg Ewing Sept. 30, 2023

Sept. 30, 2023

On 28/09/23 10:44 pm, Stefan Ram wrote: > class A: > def __init__( self ): > self.__setattr__ = self.setattr > def setattr( self, key, value ): > print( 'setattr called.' ) > > Any idea how to achieve something like this? class A: def __init__(self): self.x = 17 self.setattr = self.custom_setattr def __setattr__(self, key, value): self.setattr(key, value) def setattr(self, key, value): object.__setattr__(self, key, value) def custom_setattr(self, key, value): print('custom_setattr:', key, '=', value) a = A() a.x = 1 print('a.x =', a.x) -- Greg

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error of opening Python
by Abdelkhelk ashref salay eabakh Sept. 29, 2023

Sept. 29, 2023

Dear Python team, This is my not first time using Python, I tried to launch Python and it showed "Python 3.11.3 (tags/v3.11.3:f3909b8, Apr 4 2023, 23:49:59) [MSC v.1934 64 bit (AMD64)] on win32 Type "help", "copyright", "credits" or "license" for more information." I don't know what this meant and how to fix this. Could you please help me? Thank you very much. Kind regards

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Re: upgrade of pip on my python 2.7 version
by Zuri Shaddai Kuchipudi Sept. 28, 2023

Sept. 28, 2023

On Wednesday, 27 September 2023 at 23:33:02 UTC+2, Chris Angelico wrote: > On Thu, 28 Sept 2023 at 07:27, Mats Wichmann via Python-list > <pytho...(a)python.org> wrote: > > > > Upgrading to Python 3 is the best answer... except when it isn't. If > > you want to convert a small project it's usually not too hard; and using > > a conversion tool can work well. > Just remember that Python 2.7.18, the very last version of Python 2, > was released in 2020 and has not changed since. There are not even > security patches being released (at least, not from python.org - but > if you're using a different distribution of Python, you are also quite > possibly using their package manager rather than pip). Staying on a > version of Python that hasn't had new features since 2010 and hasn't > had bug fixes since 2020 is going to become increasingly problematic. > > Convert your code. Pay the price in development time now and then reap > the benefits, rather than paying the price when you run into a massive > issue somewhere down the track and there's no options left to you. > > Convert while you still have the luxury of running the old code. > > ChrisA but how do i convert it chris just downloading the python version 3 will solve my issue? and what about the changes

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venv --upgrade 3.12.0rc2 --> 3.12.0rc3 failure
by Robin Becker Sept. 28, 2023

Sept. 28, 2023

Attempting venv upgrade 3.12.0rc2 --> 3.12.0rc3 I find pyvenv.cfg changes, but the virtual python doesn't. I guess this ought to be a bug. > user@host:~/devel > $ ~/LOCAL?3.12.0rc2/bin/python3 -m venv xxx > bash: /home/user/LOCAL?3.12.0rc2/bin/python3: No such file or directory > user@host:~/devel > $ ~/LOCAL/3.12.0rc2/bin/python3 -m venv xxx > user@host:~/devel > $ xxx/bin/python -c'import sys;print(sys.version)' > 3.12.0rc2 (main, Sep 9 2023, 17:53:34) [GCC 13.2.1 20230801] > user@host:~/devel > $ cat xxx/pyvenv.cfg > home = /home/user/LOCAL/3.12.0rc2/bin > include-system-site-packages = false > version = 3.12.0 > executable = /home/user/LOCAL/3.12.0rc2/bin/python3.12 > command = /home/user/LOCAL/3.12.0rc2/bin/python3 -m venv /home/robin/devel/xxx > user@host:~/devel > $ ~/LOCAL/3.12.0rc3/bin/python3 -m venv --upgrade xxx > user@host:~/devel > $ xxx/bin/python -c'import sys;print(sys.version)' > 3.12.0rc2 (main, Sep 9 2023, 17:53:34) [GCC 13.2.1 20230801] > user@host:~/devel > $ cat xxx/pyvenv.cfg > home = /home/user/LOCAL/3.12.0rc3/bin > include-system-site-packages = false > version = 3.12.0 > executable = /home/user/LOCAL/3.12.0rc3/bin/python3.12 > command = /home/user/LOCAL/3.12.0rc3/bin/python3 -m venv --upgrade /home/robin/devel/xxx > user@host:~/devel > $ # check versions > user@host:~/devel > $ ~/LOCAL/3.12.0rc2/bin/python3 -c'import sys;print(sys.version)' > 3.12.0rc2 (main, Sep 9 2023, 17:53:34) [GCC 13.2.1 20230801] > user@host:~/devel > $ ~/LOCAL/3.12.0rc3/bin/python3 -c'import sys;print(sys.version)' > 3.12.0rc3 (main, Sep 27 2023, 09:35:10) [GCC 13.2.1 20230801] > user@host:~/devel > $ -- Robin Becker

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Installing package as root to a system directory
by Loris Bennett Sept. 28, 2023

Sept. 28, 2023

Hi, I use poetry to develop system software packages as a normal user. To install the packages I use, again as a normal user export PYTHONUSERBASE=/some/path pip3 install --user somepackage.whl and add /some/path to /usr/lib64/python3.6/site-packages/zedat.pth This works well enough, but seems to me to be a little clunky, mainly because the files don't then belong to root. The most correct way, in my case, would probably be to create an RPM out of the Python package, but that seems like it would be too much overhead. What other approaches to people use? Cheers, Loris -- This signature is currently under constuction.

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path to python in venv
by Larry Martell Sept. 28, 2023

Sept. 28, 2023

I was under the impression that in a venv the python used would be in the venv's bin dir. But in my venvs I see this in the bin dirs: lrwxrwxrwx 1 larrymartell larrymartell 7 Sep 27 11:21 python -> python3 lrwxrwxrwx 1 larrymartell larrymartell 16 Sep 27 11:21 python3 -> /usr/bin/python3 Googling this I read: The presence of symbolic links like python and python3 in the bin directory of your virtual environment pointing to the system Python executable (/usr/bin/python) suggests that the virtual environment was created using the system Python interpreter rather than a standalone Python installation. This can happen if you create a virtual environment using a system-wide Python interpreter, and the virtual environment inherits some of the symbolic links or shortcuts from the system Python installation. In this case, your virtual environment is not fully isolated because it still relies on the system Python interpreter. Not sure what this really means, nor how to get python to be in my venv.

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Re: path to python in venv
by Jon Ribbens Sept. 27, 2023

Sept. 27, 2023

On 2023-09-27, Larry Martell <larry.martell(a)gmail.com> wrote: > On Wed, Sep 27, 2023 at 12:42 PM Jon Ribbens via Python-list ><python-list(a)python.org> wrote: >> On 2023-09-27, Larry Martell <larry.martell(a)gmail.com> wrote: >> > I was under the impression that in a venv the python used would be in >> > the venv's bin dir. But in my venvs I see this in the bin dirs: >> > >> > lrwxrwxrwx 1 larrymartell larrymartell 7 Sep 27 11:21 python -> python3 >> > lrwxrwxrwx 1 larrymartell larrymartell 16 Sep 27 11:21 python3 -> >> > /usr/bin/python3 >> ... >> > Not sure what this really means, nor how to get python to be in my venv. >> >> WHy do you want python to be "in your venv"? > > Isn't that the entire point of a venv? To have a completely self > contained env? So if someone messes with the system python it will not > break code running in the venv. The main point of the venv is to isolate the installed packages, rather than Python itself. I'm a bit surprised your symlinks are as shown above though - mine link from python to python3.11 to /usr/bin/python3.11, so it wouldn't change the version of python used even if I installed a different system python version.

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Re: upgrade of pip on my python 2.7 version
by Zuri Shaddai Kuchipudi Sept. 27, 2023

Sept. 27, 2023

On Wednesday, 27 September 2023 at 21:32:53 UTC+2, Mats Wichmann wrote: > On 9/27/23 05:17, Zuri Shaddai Kuchipudi via Python-list wrote: > > hello everyone this the error that im getting while trying to install and upgrade pip on what is the solution for it? > > > > C:\repository\pst-utils-pc-davinci-simulator>pip install > > You are using pip version 7.0.1, however version 23.2.1 is available. > > You should consider upgrading via the 'pip install --upgrade pip' command. > > You must give at least one requirement to install (see "pip help install") > > > > C:\repository\pst-utils-pc-davinci-simulator>pip install --upgrade pip > > You are using pip version 7.0.1, however version 23.2.1 is available. > > You should consider upgrading via the 'pip install --upgrade pip' command. > > Collecting pip > > Using cached https://files.pythonhosted.org/packages/ba/19/e63fb4e0d20e48bd2167bb7e857ab… > > Complete output from command python setup.py egg_info: > > Traceback (most recent call last): > > File "<string>", line 20, in <module> > > File "c:\users\kuchipz\appdata\local\temp\pip-build-gc4ekm\pip\setup.py", line 7 > > def read(rel_path: str) -> str: > > ^ > > SyntaxError: invalid syntax > PyPI *should* be returning a compatible version of pip to upgrade to. > pip itself has long since dropped support for 2.7, and the version > you're trying to force is pretty clear: > > pip 23.2.1 > > Meta > License: MIT License (MIT) > Author: The pip developers > Requires: Python >=3.7 > ... > Classifiers > Development Status > 5 - Production/Stable > Intended Audience > Developers > License > OSI Approved :: MIT License > Programming Language > Python > Python :: 3 > Python :: 3 :: Only > ... > > So "don't do that". > > Why it's trying to select an incompatible version when you ask to > upgrade is not something I'd like to speculate on, for me personally > that's a surprise. Maybe something else you did before? > > Also make sure you're using a pip that matches your Python. It's usually > safer if you invoke it as: > > python -m pip install --upgrade pip > > (or whatever the precise name of your Python 2 interpreter actually is) the code that i want to run and all the libraries are written for python 2 but i have seen a video where the person showed the 2to3 pip method in which it rewrites the code in python 3 and shows all the necessary changes.

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