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Python Package Management

Perhaps unwise to nest this topic in the “Programming” category, as mastering this is as important to a system administrator as managing the package management system of one’s preferred “*nix” distribution. Nevertheless, let us dive into the realm of python package management.

The evolution of virtualenvs in python.

Python has evolved rather quickly in comparison to other programming languages. Yes, there are other newer, more trendy programming languages of our time, but by comparison of it’s predecessors, Python exploded into the mainstream of computational usage. The point of this being, because of python’s popularity and rapid development it encountered problems that other programming languages have not had to endure. Mainly, by this we are referring to the issue of maintaining version compatilibility.

The issue with python and maintaining version compatilibility with a module, is simply one module will be written using one version, while another module will be written using a version that is either a few versions behind or a few versions forward. In which case, in a basic installation of python, only one version can remain, thus it is a matter of breaking the dependencies of one package in order to satisfy the requirements of another. Now, take this example of two packages with conflicting requirements and muiltiply it times 158, and what you will then have is a fucking mess.

To resolve this, one dude came up with the clever idea to contain the dependencies of a module within a virtual environment. Who this brilliant dude was, I have no idea, but he was clever, and pretty soon use of virtual environments became extremely common. This unfortunately did not completely resolve the problem, but in actuality created another issue. The process to create those virtual environments was rather tedious and time consuming, it all required a large amount of space to store an entire functioning implementation of python in it’s own environment. So, another clever little fellow came up with a way to make creation of those environments faster, and then later on more fellers jumped in and created their own implementations of short cutting the virtualenv create process.

To summarize, what is now a long winded dribble, Python now has finally decided that creation of virtualenvs is obviously the path of the future, and have implemented this process in their main package management application, pip.

TODO: Finish this damn essay later.

Python Virtual Environments Managers

As mentioned above, the following are applications used to manage python virtual environments on your system.

Pipenv

One of the original shortcuts to management virtual environments.

To install: pip3 install --user -U pipenv

To use, you will need to clone the repository of the module/application you want to use, and then cd inside of it.

1. pipenv --pythonX.X will install an environment for the module with python version x.x.
2. pipenv install will create a virtual environment and install all dependencies listed in requirements.txt.
3. pipenv run $application will run the $application in the virtual env.
4. pipenv shell will open a shell in the virtual environment.

Pipx

Takes a stab at seamlessly managing all user installed python applications, to make life so much easier. If you can’t tell, I am a little partial to this tool.

To install: pip3 install --user -U pipx

Unlike with pipenv, you will not need to clone the repository, or be with it. Pipx can be executed from anywhere as long as it is in your $PATH. This is because, pipx uses python’s official repository of packages, but it can be used to install from repositories as well.

1. pipx install $PACKAGE will install the $PACKAGE, and your done.
2. pipx self update will update pipx.

You see how much easier it is.

Poetry

Poetry is more aimed at the development side of things than pipx, and does take a few more steps to setup than pipx as well. To setup a project is very similar to pipenv, although the version managment and environment configuration is exponentially more robust. If you want to develop python applications or modules, this is undoubtedly your best choice of those listed here.

To install: pip3 install --user -U poetry

Just like pipenv, you will need to be located within the project repository in order to execute successfully.

1. poetry init will initialize poetry for the project and generate your pyproject.toml file. This file is where you can customize numerous details of your development environtment.
2. poetry install installs all the dependencies with you just gave to poetry in the previous command, and will crete your virtual env.
3. poetry run will allow you to run and test project.
4. poetry shell will allow you to open a shell in the environment of your project.