Install git python library through python regardless of OS - python

I have developed a tool that my team can use after running the setup.py script. The tool requires this library: https://github.com/c2nes/javalang
How can I make my python setup script install this library on their computer regardless of what OS they are on. They can't run my tool without that library (Some people are on windows, mac, and linux.)

pip can install projects on Github as a dependency too!
All you need to do is, in your requirements.txt, add a line like following:
..
git+https://github.com/c2nes/javalang.git
then install the dependency using:
$ pip install -r requirements.txt
What you are looking for exists on PyPI. Instead of git+https://.. line above, just say: javalang. Oh and BTW, unless they are running old versions of Python, they should already have pip installed. If they don't use your operating systems package manager or get-pip.py as you said.

Related

How to debug python system library modules [duplicate]

Two options in setup.py develop and install are confusing me. According to this site, using develop creates a special link to site-packages directory.
People have suggested that I use python setup.py install for a fresh installation and python setup.py develop after any changes have been made to the setup file.
Can anyone shed some light on the usage of these commands?
python setup.py install is used to install (typically third party) packages that you're not going to develop/modify/debug yourself.
For your own stuff, you want to first install your package and then be able to frequently edit the code without having to re-install the package every time — and that is exactly what python setup.py develop does: it installs the package (typically just a source folder) in a way that allows you to conveniently edit your code after it’s installed to the (virtual) environment, and have the changes take effect immediately.
Note: It is highly recommended to use pip install . (regular install) and pip install -e . (developer install) to install packages, as invoking setup.py directly will do the wrong things for many dependencies, such as pull prereleases and incompatible package versions, or make the package hard to uninstall with pip.
Update:
The develop counterpart for the latest python -m build approach is as follows (as per):
From the documentation. The develop will not install the package but it will create a .egg-link in the deployment directory back to the project source code directory.
So it's like installing but instead of copying to the site-packages it adds a symbolic link (the .egg-link acts as a multiplatform symbolic link).
That way you can edit the source code and see the changes directly without having to reinstall every time that you make a little change. This is useful when you are the developer of that project hence the name develop. If you are just installing someone else's package you should use install
Another thing that people may find useful when using the develop method is the --user option to install without sudo. Ex:
python setup.py develop --user
instead of
sudo python setup.py develop

"yum install package" or "python setup.py install" in CentOS?

I was wondering how the above "yum install package" & "python setup.py install" are used differently in CentOS? I used yum install ... all the time. However, when I try to do python setup.py install, I always get: this setup.py file couldn't be found even though its path shows up under echo $PATH, unless I try to use it in its current directory or use the absolute path.
When you type python setup.py install, your shell will check your $PATH for the python command, and run that. Then, python will be examining its arguments, which are setup.py install. It knows that it can be given the name of a script, so it looks for the file called setup.py so it can be run. Python doesn't use your $PATH to find scripts, though, so it should be a real path to a file. If you just give it the name setup.py it will only look in your current directory.
The source directory for a python module should not, ideally, be in your $PATH.
yum install is a command that will go to a package repository, download all the files needed to install something, and then put them in the right place. yum (and equivalents on other distributions, like apt for Debian systems) will also fetch and install any other packages you need, including any that aren't python modules.
Python has a package manager, too. You may also find using pip install modulename or pip install --user modulename (if you don't have administrative rights) easier than downloading and installing the module by hand. You can often get more recent versions of modules this way, as the ones provided by an operating system (through yum) tend to be older, more stable versions. Sometimes the module is not available through yum at all. pip can't install any extra packages that aren't python modules, though.
If you don't have pip already (it comes with Python3, but might need installing separately for Python2, depending on how it was set up), then you can install it by following the instructions here: https://pip.pypa.io/en/stable/installing/

How to determine if a package was installed via develop or install commands

I am developing a Python package. Sometimes, I want to use the latest development version, sometimes I want to use the release version. I am very lazy so want whatever I call to tell me whether or not it is a development version or a release version.
So, once a python package is installed, is there a way to determine whether it was installed using
python setup.py develop
or
python setup.py install --user
For argument's sake, let's assume that the package only has a console entry point. I could check that the package is under $HOME like so:
if os.environ['HOME'] in os.path.dirname(os.path.realpath(__file__)):
print("⚠ You might be using the development version")
This works fine if the install command was python setup.py install but not if installing it locally.

Difference between 'python setup.py install' and 'pip install'

I have an external package I want to install into my python virtualenv from a tar file.
What is the best way to install the package?
I've discovered 2 ways that can do it:
Extract the tar file, then run python setup.py install inside of the extracted directory.
pip install packagename.tar.gz from example # 7 in https://pip.pypa.io/en/stable/reference/pip_install/#examples
Is if there is any difference doing them in these 2 ways.
On the surface, both do the same thing: doing either python setup.py install or pip install <PACKAGE-NAME> will install your python package for you, with a minimum amount of fuss.
However, using pip offers some additional advantages that make it much nicer to use.
pip will automatically download all dependencies for a package for you. In contrast, if you use setup.py, you often have to manually search out and download dependencies, which is tedious and can become frustrating.
pip keeps track of various metadata that lets you easily uninstall and update packages with a single command: pip uninstall <PACKAGE-NAME> and pip install --upgrade <PACKAGE-NAME>. In contrast, if you install a package using setup.py, you have to manually delete and maintain a package by hand if you want to get rid of it, which could be potentially error-prone.
You no longer have to manually download your files. If you use setup.py, you have to visit the library's website, figure out where to download it, extract the file, run setup.py... In contrast, pip will automatically search the Python Package Index (PyPi) to see if the package exists there, and will automatically download, extract, and install the package for you. With a few exceptions, almost every single genuinely useful Python library can be found on PyPi.
pip will let you easily install wheels, which is the new standard of Python distribution. More info about wheels.
pip offers additional benefits that integrate well with using virtualenv, which is a program that lets you run multiple projects that require conflicting libraries and Python versions on your computer. More info.
pip is bundled by default with Python as of Python 2.7.9 on the Python 2.x series, and as of Python 3.4.0 on the Python 3.x series, making it even easier to use.
So basically, use pip. It only offers improvements over using python setup.py install.
If you're using an older version of Python, can't upgrade, and don't have pip installed, you can find more information about installing pip at the following links:
Official instructions on installing pip for all operating systems
Instructions on installing pip on Windows (including solutions to common problems)
Instructions on installing pip for Mac OX
pip, by itself, doesn't really require a tutorial. 90% of the time, the only command you really need is pip install <PACKAGE-NAME>. That said, if you're interested in learning more about the details of what exactly you can do with pip, see:
Quickstart guide
Official documentation.
It is also commonly recommended that you use pip and virtualenv together. If you're a beginner to Python, I personally think it'd be fine to start of with just using pip and install packages globally, but eventually I do think you should transition to using virtualenv as you tackle more serious projects.
If you'd like to learn more about using pip and virtualenv together, see:
Why you should be using pip and virtualenv
A non-magical introduction to Pip and Virtualenv for Python beginners
Virtual Environments
python setup.py install is the analog of make install: it’s a limited way to compile and copy files to destination directories. This doesn’t mean that it’s the best way to really install software on your system.
pip is a package manager, which can install, upgrade, list and uninstall packages, like familiar package managers including: dpkg, apt, yum, urpmi, ports etc. Under the hood, it will run python setup.py install, but with specific options to control how and where things end up installed.
In summary: use pip.
The question is about the preferred method to install a local tarball containing a python package, NOT about the advantage of uploading package to an indexing service like PyPi.
As lest I know some software distributor does not upload their package to PyPi, instead asking developers to download package from their website and install.
python setup.py install
This can work but not recommended. It's not necessary to unwrap the tarball file and go into it to run setup.py file.
pip install ../path/to/packagename.tar.gz
This is the way designed and preferred. Concise and align with PyPi-style packages.
More information about pip install can be found here: https://pip.readthedocs.io/en/stable/reference/pip_install/

How do Homebrew, PIP, easy_install etc. work so that I can clean up

I have a problem that comes from me following tutorials without really understanding what I'm doing. The root of the problem I think is the fact that I don't understand how the OS X filesystem works.
The problem is bigger than Python but it was when I started learning about Python that I realized how little I really understand. So in the beginning I started following tutorials which led me to use the easy_install command a lot and when a lot of tutorials recommended PIP I never got it running. So I have run a lot of commands and installed a lot of different packages.
As I have understood Lion comes with a python install. I have been using this a lot and from this I have installed various packages with easy_install. Is there any way to go back to default installation and begin from the very beginning? Is this something I want to do? If so why?
Is there any advantage of using a Python version I have installed with Homebrew? How can I see from where Python is run when I run the Python command?
When I do install something with either easy_install, homebrew, macports etc where do things actually end up?
Homebrew installs its software inside the /usr/local subdirectory on your Mac. OS X doesn't install anything there on its own; in fact, /usr/local is reserved for user-installed stuff. Since Homebrew never installs files outside /usr/local (and doesn't even have the ability to, unless you run brew using sudo - which is not recommended_) and OS X never installs files inside there, never the two shall mix.
easy_install and pip install files into system directories by default. That's why you have to run those commands with sudo to install packages with them.
I can't recommend virtualenv enough, regardless of which OS you're using. It installs a copy of Python, along with any packages or modules you want, inside a directory of your choosing. For example:
$ cd /tmp
$ virtualenv foo
New python executable in foo/bin/python
Installing setuptools............done.
Installing pip...............done.
$ cd foo
$ bin/pip install sqlalchemy
Downloading/unpacking sqlalchemy
Downloading SQLAlchemy-0.7.7.tar.gz (2.6Mb): 2.6Mb downloaded
Running setup.py egg_info for package sqlalchemy
[...]
Successfully installed sqlalchemy
Cleaning up...
[work, work, work]
[decide this was a bad idea]
$ cd /tmp; rm -rf foo
...and all traces of the project are now completely gone.
Use easy_install to install virtualenv into OS X itself - like you've done for those other packages - but then do all new development inside isolated directories that you can wipe clean at a moment's notice. This is pretty much the standard way of developing and deploying Python applications these days.
The advantage of using a Python installed via a package manager like Homebrew or MacPorts would be that this provides a simple way of removing the Python installation and reinstalling it. Also, you can install a more recent version than the one Mac OS X provides.

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