installation of custom library cdata for python - python-3.x

I would like to install custom library cdata for python. This library enables connection over C4C Hybris.
Unfortunately, system generates the following error while pip list (of anaconda) shows this library installed :
error image
cdata library is installed in anaconda

Faced the same problem while installing a different package, must be because of 2 different versions of python installed in your system. One solution is -
Uninstall Python from Control Panel
Uninstall Pycharm
Reinstall the latest version of both.
Better solution is changing the interpreter for that, you should go to Pycharm --> file> settings> project>project interpreter.
If there is another Python Instance, it should be up there, change it to that one. If its not in the list, click on the button that looks like Asterik/star (next to project interpreter).
CHange the interpreter.
conda update conda
python -m pip install --upgrade pip
No errors will be observed thereafter.
Moreover, read about Anaconda Virtual Envs, it will help you in long tun.

Related

"No module name adafruit_servokit"

I am working on Jetson Nano and trying to control servo motors. I am using PCA9685. I have installed all the pre-requisites for that
sudo pip3 install adafruit-circuitpython-servokit
Faced an error called
SyntaxError: future feature annotations is not defined
i updated python for that and the issue was resolved. Now the issue is that when i use python 3.8 as an interpreter in Visual studio i face the error
No module name adafruit_servokit
But when i use the python 3.6, the adafruit_servokit error is solved and the annotation error arises.
Looking forward to every suggestion. Thank you
This is because you have conflicting interpreters for your python installation.
Inside your Visual Studio terminal, try using:
python3.8 -m pip install adafruit-circuitpython-servokit
Using python -m pip install instead of just pip install is recommended. The reason is that it will use the correct interpreter for your python installation, specially if you have many versions installed. More details here: https://snarky.ca/why-you-should-use-python-m-pip/
---EDIT---
You should replace python3.8 with your target version number.

Conda vs. pip under Spyder

I have a 2-part question about conda vs. pip virtual environments. I found great information on the answers What is the difference between pip and conda? and Does Conda replace the need for virtualenv? but still have something unclear.
I have a given python project (say PR) that I need to install and further develop on a linux server (say S) where python is installed with anaconda. Now, the usage/installation instructions of PR tell me to use python to create virtual environment and pip to install all packages. That is,
python3 -m venv PR
pip install --editable . (the dot included at the end)
According to "pip install --editable ./" vs "python setup.py develop" the latter reads the file setup.py (included in PR) which contains a function setup(...) with option install_requires listing all the required packages and installs them automatically. I have tested this on my own computer (which does not have conda) and it works fine. At least no error messages.
Now I need to further develop PR on S. My question Part 1: can I use conda instead of pip to create and update virtual environment? If yes, what would be the conda command replacing pip install --editable . ? I'm positive I will later need to install other packages as well. I'm worried about conflicts between conda/pip.
On S, I have Spyder and no other python IDEs. I have never used Spyder but I'm very familiar with PyCharm (Windows) and VS Code (Linux) so I assume debugging with Spyder will be similar to those. My question Part 2 (tied to Part 1): if I have to use pip to install packages, does Spyder see those? Or can it only see conda-installed packages?
(Edit/update): Thank you Carlos for comments. I continue my question:
I created and activated the virtual environment (VE) with conda
conda create PR_venv
conda activate PR_venv
Installed pip with
conda install pip
(this upgraded pip and installed several other packages too, including newer version of python). Installed PR and its required packages with pip
pip install -e .
Now, if I run the PR package inside this active VE interactively from the terminal, everything works fine. I would like to do the same from within spyder, to get the IDE debugging abilities in my hand.
When I start spyder, open a python file to be run, click "Run" button, it crashes in the import statements.
Spyder cannot see the installed packages. It can see only the local package PR but none of the packages installed by pip for this VE.
I am not sure what is the correct question here; I'm confused how are conda VEs related to spyder/jupyter/ipython ? I cannot find information in the conda documents about this.
I cannot find from spyder documents anything about VEs. Do I have to somehow re-install the packages (how?) inside Spyder? It seems pointless because the packages are installed already.
(Edit/Update 2): The information on https://docs.spyder-ide.org/current/installation.html makes me even more confused: Spyder is presented as both a stand-alone program and as a python package. So do I have to re-install Spyder inside the VE(?!) with
conda activate PR_venv
conda install spyder
Any clarification would be appreciated. I have always thought that the IDEs are stand-alone programs and that's it. This Spyder setup twists my brains into pretzel.
(Spyder maintainer here) About your questions:
can I use conda instead of pip to create and update virtual environment?
Yes, you can. Please see here to learn about the functionality offered by conda for managing environments.
If yes, what would be the conda command replacing pip install --editable . ?
Conda doesn't offer a good replacement for that command. However, you can still use it in a conda environment, as long as all you've installed all your package dependencies with conda before running it. That would avoid mixing conda and pip packages, which usually leads to really bad results.
if I have to use pip to install packages, does Spyder see those? Or can it only see conda-installed packages?
Spyder can work with pip and conda packages without problems. Just make sure of not mixing them (as I said above) and you'll be fine. In addition, please read our documentation to learn how to connect a local Spyder instance to a remote server.
Part 1: yes I can use conda to create VE and pip to install packages
conda create PR_venv
conda activate PR_venv
conda install pip
pip install --editable .
conda list
The last line shows which packages are installed by conda and which by pip (shown as pypi)
Part 2: spyder by default cannot see the packages. Need to do two things:
conda install spyder-kernels
Open Spyder and Tools > Preferences > Python Interpreter > Use the following interpreter > [full path to VE python command]
Restart Spyder. Now it can see the packages.
(Edit:) this link is great: https://github.com/spyder-ide/spyder/wiki/Working-with-packages-and-environments-in-Spyder

Ubuntu 21.04, Virtualenv and its configuration of Python

EDIT:
In addition to the behaviour outlined below, the Python3.10 based environment seems to be ignoring packages installed with the pip -e option (development mode).
Specifically, a package installed in development mode is not listed in pip freeze (which, it does in the Python3.9 based virtual environment) and a simple import <package_name> fails. If the package is installed normally (i.e. not in development mode) everything works as expected.
I am using virtualenv to create a virtual environment based around Python 3.10. While virtualenv finishes without errors and does seem to activate, it still fails to pick up its own Python unless the PYTHONPATH environment variable has been set manually.
I am not sure if the situation I am faced with is due to Ubuntu's way of incorporating Python or the way virtualenv is setting up the environment so that it picks up a local interpreter. Here is what I have gathered this far:
My base system is an Ubuntu 21.04. It has its own Python 3 (Python3.9.5) installation which I have not touched at all except installing the python3-virtualenv package using apt.
With Python 3.10, I installed the python3.10-dev package and proceeded to create a virtual environment in the usual way:
> virtualenv -p python3.10 the_env/
> source the_env/bin/activate
Although this looks OK so far, this environment does not have any information about its own site-packages directory. Not even the one that virtualenv is supposed to be creating which includes pip. In this installation, if you try to > pip --version you simply get an error that
the pip package does not exist (the pip "executable" location is picked up correctly, but because the interpreter does not know anything about its site-packages it fails to start pip properly).
Long story short, I created two environments, one based on Python3.9 (which works perfectly) and one based on Python3.10 (which does not work) and did a very simple test in each environment:
> python -m site
On the Python3.9 environment, sys.path includes a path that leads all the way to this particular environment's site-packages
On the Python3.10 environment, sys.path does not include that particular path but still includes the typical paths you expect to find (e.g. those pointing to the interpreter itself and the top environment directory but not the specific path that points to the site-packages location.
Following this, I defined a PYTHONPATH manually, before activating the environment which points exactly to the site-packages for that particular environment and everything worked as expected.
I suspect that this might be something to do with the fact that my system's Python is 3.9 which means that the USER_SITE variable is valid while in the case of Python3.10, it is not (because, I do not have a use for it, this is just a virtual environment I am creating). So, I suspect that this might be throwing off the way the site module determines where things are.
As I am not sure, I would like to ask the following:
Could this be something to do with the way Ubuntu handles the Python installation that might just be creating this small problem with virtual environments?
Could the problem be with virtualenv that does not explicitly specify a PYTHONPATH?
Could this behaviour be something of a corner case of the site module?
What worked for me is an installation from source. After unpacking the source code, as a summary:
$ ./configure --enable-optimizations --with-ensurepip=install --prefix=/path/to/install/to/
$ make -j
$ make test
$ make install
$ /path/to/install/to/bin/python3.10 -m venv /path/to/test
$ source /path/to/test/bin/activate
$ pip list
Package Version
---------- -------
pip 21.2.4
setuptools 58.1.0
WARNING: You are using pip version 21.2.4; however, version 21.3.1 is available.
You should consider upgrading via the '/path/to/test/bin/python3.10 -m pip install --upgrade pip' command.
$ python -m pip install --upgrade pip
[...]
$ pip list
Package Version
---------- -------
pip 21.3.1
setuptools 58.1.0
Edit
As mentioned below, I believe the reason why the procedure above just works is simply that when building and installing Python from source, the installation simply will be correct, which I suspect the 3.10 installation in Ubuntu 21.04 is not.
I made my Python installation from source somewhere under my home directory, in order to not risk messing things up, and I also did not permanently modify the PATH.
Setting the path to $PATH:/path/to/install/to/bin should be fine however, either permanently, or just when running mkvirtualenv.
Doing that, my new installation even seems to integrate seamlessly with my system's virtualenvwrapper.
I don't really need to be on the Python leading edge myself, but if I did, I would definitely make myself independent of Ubuntu's latest development by using the procedure described above.
By the way, if I update pip directly in the Python installation built from source, I will no longer get the message about the older pip (see above) when I install new virtual environments.
Edit 2
Bug reported to Ubuntu:
https://bugs.launchpad.net/ubuntu/+source/python3.10/+bug/1955742
Edit 3
Also, since Ubuntu 21.04 has end of life in a month or so, upgrading to 21.10 could really make sense. I have just tried that, and it seems that Python 3.10 virtual environments work just fine in that release.
With the advent of Ubuntu 22.04 (which caused a few minor issues with some specific python virtualenv setups I had) and having already spent some time figureing this out, I ended up switching to using pyenv.
Pyenv made it very easy to install any python version and any number of virtual environments within it which can be further customised in complete isolation.
The only thing to be careful of is installing all necessary python prerequisites before installing a specific version to avoid missing functionality from some packages (e.g. not including the lzma library will generate an ominous warning from pandas ("your python installation is incomplete..."). This can be ignored if you are not using that functionality or otherwise, easily fixed.
I think that this is a better option overall if you have to manage different versions and specific configurations for python, even across distros.
This solution is very close to the one suggested before ("install from source") so I will be accepting that one and leave my contribution as additional information about this problem.

How to find out the installed (Python) libraries in Visual Studio Code

I have been coding Python 3.7 using Visual Studio Code on Windows 10. Recently, I have taken over a new project, which calls for some newer and different libraries. Hence, for whatever reason, I decided not to customise my libraries, but to install Anaconda, and install the corresponding libraries into it.
However, since I cannot remember all the libraries I have already installed in Visual Studio Code (e.g. numPy, matplotlib, etc.), I'd like to ask if there is any way to get a list of the libraries I added on to my Python installation.
I appreciate your comments in advance!
Cheers,
Sina
You can list your installed libraries using pip.
pip list will give you the list of all installed libraries for its python installation.
NB: Just make sure you are using the pip.exe from the good install of python, in your case the 3.7 you mentionned
You can use the pip list command to show all installed packages.
Windows:
$ py -m pip list [options]
Linux:
$ python -m pip list [options]
Documentation: https://pip.pypa.io/en/stable/cli/pip_list/
you can use conda list to list all the packages installed in anaconda environment

Update Biopython in Ipython shell

python newbie here, today I updated biopython to v1.70. I use spyder/IPython shell for most of my work. if it makes any sense, the version of biopython seems updated in the python console (spyder), and windows command terminal python installation, but IPython console is still showing older version. Should that be updated separately, and if yes, how. Thanks for answers.
For Anaconda on Windows, using the Command Prompt (what you get when typing cmd or clicking on Command Prompt in the Start menu) is discouraged1 since the latest release (May '17).
Instead, use Anaconda Prompt or the graphical Anaconda Navigator (both located under the Anaconda folder in the Start menu). You should use them for installing packages, as well as for running apps (e.g. Spyder, IPython).
Also, I recommend you use conda to install packages. conda is the native package manager for Anaconda, and it manages dependencies (packages required to run other packages) better than pip.
So, what you can try is:
Start --> Anaconda Prompt, and then
conda install biopython
ipython
At the time of writing, the official conda repository contains biopython 1.6.9. If you really need 1.7.0, use conda install -c conda-forge biopython (conda-forge is an alternative package repository which is maintained by the community).
[1] See the 2nd bullet on Anaconda 4.4.0 release notes.

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