I am confused as to what exactly pip install (package) does. In my django project, I wanted to install a package and thought that I only needed to include it in the settings.py INSTALLED_APPS. However I also needed to run the command pip install (package) as well.
Why is this the case? I thought that pip install only installed packages locally? The package seems to also work through my remote repository from another user as well which is why I am confused
pip is a package manager. When you pip install (package), it searches PyPI (the Python Package Index) for a package with the name (and potentially, the version) that you have provided. It then downloads the package and installs it.
After the package has been installed locally, you can reference it in your INSTALLED_APPS in your Django settings file.
Please read more details here: https://realpython.com/what-is-pip/
Related
I have a python project that uses tools/programs from the command line command called pip.
How do i ensure that the user has all the tools i'm using on their computer?
Do i have to include a readme that states you need the following tools in order to properly run the program, or is there some sort of function or module for me that can automatically install the missing features?
Oh, and i'm fairly new to Python, so maybe i just do not understand how pip works. Can i just use os.system("pip install something")? And what if i wanna be not platform specific?
The convention is to include a requirements.txt which contains information on which packages need to be installed. You can read more at the official documentation for pip.
However, since generating that manually can be painful, there are tools like pipreqs which examines your project and generates a requirements.txt file for you by comparing your imports against those which are found through official pip repositories.
Once the requirements.txt file is generated, it can be installed this way: pip install -r requirements.txt.
I am trying install a Django app on Heroku. My app needs pyke3. The recommended way for installing pyke3 is to download pyke3-1.1.1.zip https://sourceforge.net/projects/pyke/files/pyke/1.1.1/ and then install (into a virtualenv if desired) using the instructions on http://pyke.sourceforge.net/about_pyke/installing_pyke.html. How do I install pyke3 on heroku? Is there a way to add this to the requirements.txt, and how will heroku know where to get the pyke3 zip file?
From pip's docs:
pip supports installing from PyPI, version control, local projects, and directly from distribution files.
So, pip supports installing packages directly from links. All you have to do is put the link to the required package in your requirements file.
To download the package pyke3-1.1.1.zip, add this link in your requirements:
https://sourceforge.net/projects/pyke/files/pyke/1.1.1/pyke3-1.1.1.zip/download
The question
Ansible is a python moduel, installable via pip. It relies on several dependencies, also pip modules. Is it possible to "roll up" all of those dependencies and Ansible itself into some sort of a single package, that can be installed offline, without root? It's highly preferable to not need pip for the install, although it will be available for package creation.
Extra background
I'm trying to install Ansible on one of our servers. The server does not have access to the internet, there is no root access. Pip is not installed, but Python is. It is possible to get pip installed there, but might be complicated. The only way to get anything on the server is via an internal tar.gz package sharing solution.
I've tried fiddling around with rpm, saving dependencies, but the absence of root access put an end to that.
Use pip on an internet-connected machine to download all the deps to a local dir with --download and -r requirements.txt, then drop that dir on the disconnected machine with pip installed, and install using --no-index and --find-links=(archive dir).
See https://pip.pypa.io/en/latest/user_guide/#fast-local-installs
The output of pip freeze on my machine has included the following odd line:
command-not-found==0.2.44
When trying to install requirements on a different machine, I got the obvious No distributions at all found for command-not-found==0.2.44. Is this a pip bug? Or is there any real python package of that name, one which does not exist in pypi?
Indeed, as mentioned in the follow up comments, Ubuntu has a python package, installed via dpkg/apt that is called "python-commandnotfound"
$apt-cache search command-not-found
command-not-found - Suggest installation of packages in interactive bash sessions
command-not-found-data - Set of data files for command-not-found.
python-commandnotfound - Python 2 bindings for command-not-found.
python3-commandnotfound - Python 3 bindings for command-not-found.
As this is provided via apt, and not available in the pypi repo, you won't be able to install it via pip, but pip will see that it is installed. For the purposes of showing installed packages, pip doesn't care if a package is installed via apt, easy_install, pip, manually, etc.
In short, if you actually need it on another host (which I assume you don't) you'll need to apt-get install python-commandnotfound.
I'm wondering if there's a way to "install" single-file python modules using pip (i.e. just have pip download the specified version of the file and copy it to site-packages).
I have a Django project that uses several 3rd-party modules which aren't proper distributions (django-thumbs and a couple others) and I want to pip freeze everything so the project can be easily installed elsewhere. I've tried just doing
pip install git+https://github.com/path/to/file.git
(and tried with the -e tag too) but pip complains that there's no setup.py file.
Edit: I should have mentioned - the reason I want to do this is so I can include the required module in a requirements.txt file, to make setting up the project on a new machine or new virtualenv easier.
pip requires a valid setup.py to install a python package. By definition every python package has a setup.py... What you are trying to install isn't a package but rather a single file module... what's wrong with doing something like:
git clone git+https://github.com/path/to/file.git /path/to/python/install/lib
I don't quite understand the logic behind wanting to install something that isn't a package with a package manager...