PyPi + setuptools: Developing in `python3.10`; Running on `python3.8` - python-3.x

I enjoy developing in python3.10 with it's newer features like match/case and type hints.
It is my understanding that more people will have python3.8 installed on their system since it is the default python3 version (Default for sudo apt install python3).
Is there any way to allow users with python3.8 to run my PyPi packages? Is it generally good practice to omit these newer features so that your package can reach a larger audience?

Related

how does conda check packages for compatibility?

In my environments created with anaconda, the same packages installed with conda are not compatible when I try to install with pip.
Is there a difference how pip and conda handle dependencies?
Here an example of requirements.txt
# Python version 3.9.13
django==2.2.5
djangorestframework==3.14.0
gensim==4.1.2
joblib==1.1.1
nltk==3.7
numpy==1.21.5
openpyxl==3.0.9
pandas==1.4.4
pickleshare==0.7.5
scikit-learn==1.1.3
seaborn==0.12.0
spacy==3.3.1
tensorflow==2.9.1
unidecode==1.2.0
conda allows you to create the environment, pip reports incompatibility between django and djangorestframework.
Conda checks, if all packages that will end up in the environment are compatible with each other and tries to find the optimal solution - considering all package versions.
Pip is less strict and only checks, if the new package is compatible with the existing ones. It doesn't change versions of the previously installed packeages.
Pip installs packages from from pypi.org, while conda installs from anaconda.org. The packages are not exactly the same, since the Anaconda staff authors new packages and tries to increase their compatibility with the older ones.
However, sometimes you are not interested in 100% compatibility but just want to use the latest features. Then pip is good enough because your unit tests will tell you if something goes wrong.

Should i remove Python 3.6 while installing Python 3.8 or newer?

I tried to install a certain python module that required python 3.6 minimum to work properly so I checked my version using python --version which gave me the output of Python 2.7.17 and then used python3 --version giving me Python 3.6.9. Now, I know for a fact that i have Python 3.8 installed because I ran apt install python3.8 just before checking the version.
If someone wants to know what my system is running; I am currently running Elementary OS 5.1.7 Hera.
EDIT:
(IDK what term to use, I want to say I am done going through answers, and I liked none.)
After a while of whacking my brain, I decided not to uninstall the 3.6 version as It may have version specific modules which if removed may cause other installed programs to break.
Since I just use Linux for my college-work, It wont matter if more than one versions are installed anyway.
Sorry for any mistakes I may have made, I was never good at this kind of things.
Use conda to install and manage different versions of Python (or lots of other software, for that matter). Install different Python versions in separate conda environments. For example:
Find what python versions are available:
conda search python
Output (as of the time of writing, in the future I expect that the latest Python versions will be higher):
Loading channels: done
# Name Version Build Channel
python 1.0.1 0 conda-forge
python 1.2 0 conda-forge
...
python 3.9.0 h88f2d9e_1 pkgs/main
python 3.9.0 ha017127_4_cpython conda-forge
Install the Python versions you need in separate environments. Here, install Python 3.9.0 in environment named python39:
conda create --name python39 python=3.9.0
Switching environments is easy:
conda activate python39
# python is now 3.9.0
conda deactivate
# back to the default python
or (deprecated now):
source activate python39
source deactivate
SEE ALSO:
conda docs: Managing environments
This question is more appropriate for Unix & Linux.
Python installations (more generally, versioned installations of software) co-exist on linux using version numbers. You can likely run Python 3.8 using the python3.8 command (or else, locate where you installed it and run from there / add the location to the PATH environment variable to run directly).
Likewise, for each python version you can install its own package manager (e.g. install pip3.8 by python3.8 -m pip install pip) and use it to install packages for that python version. (As different projects require different sets of packages, the general practice is to create a "virtual environment", i.e. a separate copy of the needed version of python, pip and their package installation folders for each project, and install the required packages there - for more information see e.g. this excellent answer).
Regarding the command python3 (usually /usr/bin/python3) is just a symbolic link, you can replace it with the version you like (as long as it remains compatible with what the system expects - i.e. python3 of version no less than your built-in python3/python3-minimal, otherwise you will probably break something), e.g. assuming which python3 gives you /usr/bin/python3, you can
sudo rm /usr/bin/python3 #remove existing link
sudo ln /usr/bin/python3.8 /usr/bin/python3 # create a new link to the version of your choice
(although a better alternative could be instead aliasing it alias python3='/usr/bin/python3.8' and adding this to ~/.bashrc).
Whatever you do, do not uninstall python3-minimal as it is - at least, on Ubuntu - required by the system and uninstalling or changing it will likely break the system.

why there is two pip are installed in my linuxmint?

2 pip are installed one is v 9 and other is v 19
how to update the pip to the latest version 19?
I m unable to download some packages due to this version conflict.
and I want only one latest pip version should be instaled, and it will be used in all the packages.
You have two different versions of python and pip installed. This is common.
/usr/local/lib/python2.7/dist-packages/pip was most likely installed by the operating system, and allows you to sudo pip install Python 2.7 packages.
/home/manish/.local/lib/python3.5/site-packages/pip is in your home folder, which means you shouldn't have to elevate your user privileges to pip install a package. This is for Python 3.5.
Managing Python versions and dependencies can be massively confusing, especially if you're just trying to follow along with a tutorial.
The best tool I can recommend to make sense of this is pyenv. It lets you install any version of python in your home folder, and allows you to switch between on a per-project (folder) basis by creating a .python-version file. pyenv.

Rationale for having having to install the python3-venv package

Some things you should know before I ask my question:
I am utterly new to both Linux & Python, and have a hard time understanding official documentation and technical answers (but have a burning desire to deeply understand both)
I am running elementary OS 0.4.1 Loki
My Python 3 version is 3.5.2. When I search the online documentation on the venv module for python 3.5.2, I get the documentation for the 3.5.6 version. I don't understand why there is no documentation for the .2 version.
So, here's my problem. I was trying to create a virtual environment using venv and proceeded thusly:
According to Python's 3.5.6 venv module documentation, a virtual environment is created using the command pyvenv /path/to/new/virtual/environment. I tried that command and got:
The program 'pyvenv' is currently not installed. You can install it by typing: sudo apt install python3-venv
I then searched documentation for newer Python versions and tried the new venv command python3 -m venv /path/to/new/virtual/environment and got the following result:
The virtual environment was not created successfully because ensurepip is not available. On Debian/Ubuntu systems, you need to install the python3-venv package using the following command. apt-get install python3-venv
In both cases, the solution seems to be to install python3-venv. My question is: What exactly am I installing by installing python3-venv: Isn't venv already part of the Standard Library? Furthermore, why do I have to install it via apt-get if it is a Python module? It is my understanding that standard library modules are imported, not installed; and that modules external to the standard library are installed via pip. Related to this, why is ensurepip not available?
Second part of my question: if installing python3-venv is the way to go, what is the proper way to create a virtual environment using venv in Python 3.5.2: pyvenv my_virtual_environment or python3 -m venv my_virtual_environment?
Don't worry about the documentation not matching the micro version number – increments in that place are only for bugfixes, so the documentation stays the same.
Your question is interesting since venv is indeed not an optional module. My guess is that the Python version shipped with your OS (or that you installed yourself) seems to come with a stripped down or no standard library. For instance, the python3.5-minimal package doesn't appear to have it. Does your Python have the other modules in the standard library?
Edit: See also this question.
Installation can be described as "putting files onto your computer, in the right place". Importing a module, however, means that you tell Python to make available some functionality. To import a module, it must be installed (e.g. in /usr/lib/python3.5 for Python 3 on my computer), and one method for installing additional modules is via apt.
The python3 -m venv my_virtual_environment method should work in 3.5 as well and is the future-proof version, so you should probably go with that.

Conda keeps trying to install all optional dependencies?

When installing Theano anaconda automatically tries to install pygpu despite this being an optional dependency. I have deleted the .theanorc file from my windows user directory.
Also when running my application Theano tries to load from the GPU. It's like it remembers somehow?
conda install theano
Fetching package metadata .............
Solving package specifications: .
Package plan for installation in environment
C:\Users\zebco\Miniconda3\envs\py35:
The following NEW packages will be INSTALLED:
libgpuarray: 0.6.9-vc14_0
pygpu: 0.6.9-py36_0
theano: 0.9.0-py36_0
Proceed ([y]/n)?
As you can see I've only specified to install theano yet conda wants to install everything including optional dependancies.
Your assumption that pygpu is optional is dependent on the package manager you are using.
Regular Python (pip)
If you are using a direct Python install (obtained using brew or Python site) then you would be using pip to install theano. This basically comes from
https://pypi.python.org/pypi/Theano/1.0.0
If you download the file and unzip it. Open setup.py, you will see below lines
install_requires=['numpy>=1.9.1', 'scipy>=0.14', 'six>=1.9.0'],
So they are set as the dependencies for this package. Which means when you install theano you will also get numpy, scipy and six.
Anaconda Python (conda)
Now coming to Anaconda python. Anaconda doesn't use a package format that PyPI or pip uses. It uses its own format. In case of Anaconda you should be using conda to install the packages you need and not pip.
Conda has channels which is nothing but a repository which has some packages available. You can install a package from any channel using below
conda install -c <channel-name> <package-name>
The default channel is conda-forge. If you look at the theano package over there
https://anaconda.org/conda-forge/theano/files
And download and extract it. There will be a info/recipe/meta.yml file. You will notice below content in the same
requirements:
build:
- ca-certificates 2017.7.27.1 0
- certifi 2017.7.27.1 py36_0
- ncurses 5.9 10
- openssl 1.0.2l 0
- python 3.6.2 0
- readline 6.2 0
- setuptools 36.3.0 py36_0
- sqlite 3.13.0 1
- tk 8.5.19 2
- xz 5.2.3 0
- zlib 1.2.11 0
run:
- python
- setuptools
- six >=1.9.0
- numpy >=1.9.1
- scipy >=0.14
- pygpu >=0.6.5,<0.7
Which specifies that if you want to run this package then pygpu is also on of its dependencies. So conda downloads pygpu as a dependency which you though was optional (which is probably true if you were using regular python and pip)
Update:
Usually, 'Optional Dependency' is an oxymoron. Something optional is not a dependency, a dependency is a software package another piece of software depends on to function for features.
One may get by without a dependency if the dependency does not interact with the package except for one atomized feature which is not being used. As a beginner I would suggest you not take this path.
I am not super familiar with Theano, but Theano can use the system's GPU to speed up its computations, and it seems to me pygpu and gpulibarray are what enable this functionality. Which means it is not optional.
I believe pygpu is 'optional' if you do not wish to use the GPU for speeding up computation (only done if the GPU is powerful enough to be useful for this).
The --no-deps command above allows you to install a package without its dependencies but that is rarely wise, unless one really knows what they are doing. As a beginner I would not recommend you go down this path yet. Conda was designed specifically to ensure scientific packages are easily managed with all necessary stuff installed without any fuss or muss. pip is a general python package manager, but is not built specifically for scientific packages.
If you wish to install theano without installing its dependencies, then you have one of three options:
use conda install theano --no-deps.
Install it using pip instead of conda, using pip install theano. This will install theano, numpy, scipy and six but not pygpu and libgpuarray.
Create a custom conda build file for Theano. Documentation is at:
https://conda.io/docs/user-guide/tasks/build-packages/index.html
Original Answer:
You probably know this already but, use this command instead:
conda install theano --no-deps
This does not install dependencies of the package. If you already have the essential dependencies installed, as it would seem, this should work out for you.
libgpuarray is a dependency of pygpu. With this command switch neither will be installed.
Can you share the .yaml file that you edited?

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