is it ok to use files inside pip packages without installing them - python

I am working on a project and I have cloned a repository from github.
After first compile I realized that the project that I cloned has some dependencies and they were in requirements.txt file.
I know I have to install these packages, but I dont want to cause I am on windows development environment and after finishing my project I am going to publish it to my ubuntu production environment and I dont want to take the hassle of double installation.
I have two options:
Using a virtualenv and installing those packages inside it
Downloading the packages and use them the direct way using import foldername
I wanna avoid the first option cause I have less control over my project and the problem gets bigger and bigger If for example I were inside another project's virtualenv and wanted to run my project's main.py file from its own virtualenv and etc... Also moving the virtualenv from windows (bat files) to linux (bash / sh files) seems ugly to me and directs me to approaches that I choose to better avoid.
The second option is my choice. for example I need to use the future package. The scenario would be downloading the package using pip download future and when done extracting the tar.gz file, inside the src folder I can see the future package folder, And I use it with import future_package.src.future without even touching anything else.
Aside from os.path problems (which assume I take care of):
Is this good practice?
I am not running the setup.py preventing any installation. Can it cause problems?
Is there any better approach that involves less work (like the second one) or the better one is my mentioned first approach?
UPDATE 1: I have extracted future and certifi packages which were part of the requirements of my project and I used them the direct way and it is working in this particular case.

Related

Python code checker for modules included in requirements.txt but unused? [duplicate]

Is there any easy way to delete no-more-using packages from requirements file?
I wrote a bash script for this task but, it doesn't work as I expected. Because, some packages are not used following their PyPI project names. For example;
dj-database-url
package is used as
dj_database_url
My project has many packages in its own requirements file, so, searching them one-by-one is too messy, error-prone and takes too much time. As I searched, IDEs don't have this property, yet.
You can use Code Inspection in PyCharm.
Delete the contents of your requirements.txt but keep the empty file.
Load your project in,
PyCharm go to Code -> Inspect code....
Choose Whole project option in dialog and click OK.
In inspection results panel locate Package requirements section under Python (note that this section will be showed only if there is any requirements.txt or setup.py file).
The section will contain one of the following messages:
Package requirement '<package>' is not satisfied if there is any package that is listed in requirements.txt but not used in any .py file.
Package '<package>' is not listed in project requirements if there is any package that is used in .py files, but not listed in requirements.txt.
You are interested in the second inspection.
You can add all used packages to requirements.txt by right clicking the Package requirements section and selecting Apply Fix 'Add requirements '<package>' to requirements.txt'. Note that it will show only one package name, but it will actually add all used packages to requirements.txt if called for section.
If you want, you can add them one by one, just right click the inspection corresponding to certain package and choose Apply Fix 'Add requirements '<package>' to requirements.txt', repeat for each inspection of this kind.
After that you can create clean virtual environment and install packages from new requirements.txt.
Also note that PyCharm has import optimisation feature, see Optimize imports.... It can be useful to use this feature before any other steps listed above.
The best bet is to use a (fresh) python venv/virtual-env with no packages, or only those you definitely know you need, test your package - installing missing packages with pip as you hit problems which should be quite quick for most software then use the pip freeze command to list the packages you really need. Better you you could use pip wheel to create a wheel with the packages in.
The other approach would be to:
Use pylint to check each file for unused imports and delete them, (you should be doing this anyway),
Run your tests to make sure that it was right,
Use a tool like snakefood or snakefood3 to generate your new list of dependencies
Note that for any dependency checking to work well it is advisable to avoid conditional import and import within functions.
Also note that to be sure you have everything then it is a good idea to build a new venv/virtual-env and install from your dependencies list then re-test your code.
You can find obsolete dependencies by using deptry, a command line utility that checks for various issues with a project's dependencies, such as obsolete, missing or transitive dependencies.
Add it to your project with
pip install deptry
and then run
deptry .
Example output:
-----------------------------------------------------
The project contains obsolete dependencies:
Flask
scikit-learn
scipy
Consider removing them from your projects dependencies. If a package is used for development purposes, you should add
it to your development dependencies instead.
-----------------------------------------------------
Note that for the best results, you should be using a virtual environment for your project, see e.g. here.
Disclaimer: I am the author of deptry.
In pycharm go to Tools -> Sync Python Requirements. There's a 'Remove unused requirements' checkbox.
I've used with success pip-check-reqs.
With command pip-extra-reqs your_directory it will check for all unused dependencies in your_directory
Install it with pip install pip-check-reqs.

setuptools "eager_resources" to executable directory

I maintain a Python utility that allows bpy to be installable as a Python module. Due to the hugeness of the spurce code, and the length of time it takes to download the libraries, I have chosen to provide this module as a wheel.
Unfortunately, platform differences and Blender runtime expectations makes support for this tricky at times.
Currently, one of my big goals is to get the Blender addon scripts directory to install into the correct location. The directory (simply named after the version of Blender API) has to exist in the same directory as the Python executable.
Unfortunately the way that setuptools works (or at least the way that I have it configured) the 2.79 directory is not always placed as a sibling to the Python executable. It fails on Windows platforms outside of virtual environments.
However, I noticed in setuptools documentation that you can specify eager_resources that supposedly guarantees the location of extracted files.
https://setuptools.readthedocs.io/en/latest/setuptools.html#automatic-resource-extraction
https://setuptools.readthedocs.io/en/latest/pkg_resources.html#resource-extraction
There was a lot of hand waving and jargon in the documentation, and 0 examples. I'm really confused as to how to structure my setup.py file in order to guarantee the resource extraction. Currently, I just label the whole 2.79 directory as "scripts" in my setuptools Extension and ship it.
Is there a way to write my setup.py and package my module so as to guarantee the 2.79 directory's location is the same as the currently running python executable when someone runs
py -3.6.8-32 -m pip install bpy
Besides simply "hacking it in"? I was considering writing a install_requires module that would simply move it if possible but that is mangling with the user's file system and kind of hacky. However it's the route I am going to go if this proves impossible.
Here is the original issue for anyone interested.
https://github.com/TylerGubala/blenderpy/issues/13
My build process is identical to the process descsribed in my answer here
https://stackoverflow.com/a/51575996/6767685
Maybe try the data_files option of distutils/setuptools.
You could start by adding data_files=[('mydata', ['setup.py'],)], to your setuptools.setup function call. Build a wheel, then install it and see if you can find mydata/setup.py somewhere in your sys.prefix.
In your case the difficult part will be to compute the actual target directory (mydata in this example). It will depend on the platform (Linux, Windows, etc.), if it's in a virtual environment or not, if it's a global or local install (not actually feasible with wheels currently, see update below) and so on.
Finally of course, check that everything gets removed cleanly on uninstall. It's a bit unnecessary when working with virtual environments, but very important in case of a global installation.
Update
Looks like your use case requires a custom step at install time of your package (since the location of the binary for the Python interpreter relative to sys.prefix can not be known in advance). This can not be done currently with wheels. You have seen it yourself in this discussion.
Knowing this, my recommendation would be to follow the advice from Jan Vlcinsky in his comment for his answer to this question:
Post install script after installing a wheel.
Add an extra setuptools console entry point to your package (let's call it bpyconfigure).
Instruct the users of your package to run it immediately after installing your package (pip install bpy && bpyconfigure).
The purpose of bpyconfigure should be clearly stated (in the documentation and maybe also as a notice shown in the console right after starting bpyconfigure) since it would write into locations of the file system where pip install does not usually write.
bpyconfigure should figure out where is the Python interpreter, and where to write the extra data.
The extra data to write should be packaged as package_data, so that it can be found with pkg_resources.
Of course bpyconfigure --uninstall should be available as well!

Debian build package: Add python virtualenv into dpkg-buildpackage to be uploaded to launchpad

I would like to pack a python program and ship it in a deb package.
For reasons (I know in 99% it is bad practice) I want to ship the program in a python virtual environment within a debian package.
I know I can do this using dh-virtualenv. This works great - generally no problem.
But the problem arises when I want to upload this to launchpad. Uploading to launchpad means uploading a source package. In terms of dh-virtualenv a source package is the package description, where the virtualenv has not been created, yet.
What happens when I upload this to launchpad is, that the package will not build, since the dh-virtualenv which is executed during the build process on launchpad will try to install python modules into the virtualenv, which means installing these from the PyPI, which will not work, since launchpad does not allow external network access.
So basically there are two possible solutions:
Approach A
Prepare the virtualenv and somehow incorporate it into the source package and having the dh build process simply "move" this prepared virtualenv to its end location. This could work with virtualenv --relocatable. BUT the relocation strips the utf-8 marker at the beginning of all python scripts, rendering all python scripts in the virtualenv broken.
Apporach B
Somehow cache all necessary python packages in the source package and have dh_virtualenv install from the cache instead of from PyPI.
This seems like to be doable with pip2pi, but certain experiements show, that it will not install packages, although they are located in the local package index.
Both approaches seem a bit clumsy and prone to errors.
What do you think of this?
What are your experiences?
What would you recommend?

Is there a way to "version" my python distribution?

I'm working by myself right now, but am looking at ways to scale my operation.
I'd like to find an easy way to version my Python distribution, so that I can recreate it very easily. Is there a tool to do this? Or can I add /usr/local/lib/python2.7/site-packages/ (or whatever) to an svn repo? This doesn't solve the problems with PATHs, but I can always write a script to alter the path. Ideally, the solution would be to build my Python env in a VM, and then hand copies of the VM out.
How have other people solved this?
virtualenv + requirements.txt are your friend.
You can create several virtual python installs for your projects, everything containing exactly those library versions you need (Tip: pip freeze spits out a requirements.txt with the exact library versions).
Find a good reference to virtualenv here: http://simononsoftware.com/virtualenv-tutorial/ (it's from this question Comprehensive beginner's virtualenv tutorial?).
Alternatively, if you just want to distribute your code together with libraries, PyInstaller is worth a try. You can package everything together in a static executable - you don't even have to install the software afterwards.
You want to use virtualenv. It lets you create an application(s) specific directory for installed packages. You can also use pip to generate and build a requirements.txt
For the same goal, i.e. having the exact same Python distribution as my colleagues, I tried to create a virtual environment in a network drive, so that everybody of us would be able to use it, without anybody making his local copy.
The idea was to share the same packages installed in a shared folder.
Outcome: Python run so unbearably slow that it could not be used. Also installing a package was very very sluggish.
So it looks there is no other way than using virtualenv and a requirements file. (Even if unfortunately often it does not always work smoothly on Windows and it requires manual installation of some packages and dependencies, at least at this time of writing.)

Distributing python code with virtualenv?

I want to distribute some python code, with a few external dependencies, to machines with only core python installed (and users that unfamiliar with easy_install etc.).
I was wondering if perhaps virtualenv can be used for this purpose? I should be able to write some bash scripts that trigger the virtualenv (with the suitable packages) and then run my code.. but this seems somewhat messy, and I'm wondering if I'm re-inventing the wheel?
Are there any simple solutions to distributing python code with dependencies, that ideally doesn't require sudo on client machines?
Buildout - http://pypi.python.org/pypi/zc.buildout
As sample look at my clean project: http://hg.jackleo.info/hyde-0.5.3-buildout-enviroment/src its only 2 files that do the magic, more over Makefile is optional but then you'll need bootstrap.py (Make file downloads it, but it runs only on Linux). buildout.cfg is the main file where you write dependency's and configuration how project is laid down.
To get bootstrap.py just download from http://svn.zope.org/repos/main/zc.buildout/trunk/bootstrap/bootstrap.py
Then run python bootstap.py and bin/buildout. I do not recommend to install buildout locally although it is possible, just use the one bootstrap downloads.
I must admit that buildout is not the easiest solution but its really powerful. So learning is worth time.
UPDATE 2014-05-30
Since It was recently up-voted and used as an answer (probably), I wan to notify of few changes.
First of - buildout is now downloaded from github https://raw.githubusercontent.com/buildout/buildout/master/bootstrap/bootstrap.py
That hyde project would probably fail due to buildout 2 breaking changes.
Here you can find better samples http://www.buildout.org/en/latest/docs/index.html also I want to suggest to look at "collection of links related to Buildout" part, it might contain info for your project.
Secondly I am personally more in favor of setup.py script that can be installed using python. More about the egg structure can be found here http://peak.telecommunity.com/DevCenter/PythonEggs and if that looks too scary - look up google (query for python egg). It's actually more simple in my opinion than buildout (definitely easier to debug) as well as it is probably more useful since it can be distributed more easily and installed anywhere with a help of virtualenv or globally where with buildout you have to provide all of the building scripts with the source all of the time.
You can use a tool like PyInstaller for this purpose. Your application will appear as a single executable on all platforms, and include dependencies. The user doesn't even need Python installed!
See as an example my logview package, which has dependencies on PyQt4 and ZeroMQ and includes distributions for Linux, Mac OSX and Windows all created using PyInstaller.
You don't want to distribute your virtualenv, if that's what you're asking. But you can use pip to create a requirements file - typically called requirements.txt - and tell your users to create a virtualenv then run pip install -r requirements.txt, which will install all the dependencies for them.
See the pip docs for a description of the requirements file format, and the Pinax project for an example of a project that does this very well.

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