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Python developers love Fedora, and Fedora loves Python. Therefore we—the Python maintenance team in Red Hat—are doing our best to provide you with all the versions of Python as soon as they are available. We even maintain some of them long after upstream developers give up.

Why is this range of support important? Some Python developers like to stay with an old and stable Python and don't change it until really necessary. Those developers frequently use Red Hat Enterprise Linux or CentOS. On the opposite side of the Gauss bell curve are developers who are always using the newest releases of Python, and even a few hardcore percent using Python pre-release versions.

It does not really matter which group you fall into because users of your applications or libraries might be doing the exact opposite. And therefore, it's a good idea to test your Python code with more than one Python version.

The tox tool allows you to run your tests in multiple Python environments with minimal configuration. But tox itself does not contain Python interpreters—and that's where Fedora enters the scene.

Comprehensive support for Python versions in Fedora

The following Python interpreters are available in the current stable release of Fedora (release 37). These are all CPython (the main Python implementation):

  • 2.7 (unsupported upstream since January 2021)
  • 3.6 (unsupported upstream since December 2021)
  • 3.7
  • 3.8
  • 3.9
  • 3.10
  • 3.11
  • 3.12 (second alpha release, as of 28th of November 2022)

Besides CPython, we also support the following versions of PyPy (Python written in Python):

  • pypy (Python 2.7)
  • pypy3.7
  • pypy3.8
  • pypy3.9

Fast delivery downstream

That's a lot of Pythons! But if you are a bleeding-edge user, you care about our speed of delivery as well. So let's take the last stable Python 3.11 as an example.

The first alpha version, released on October 5th, 2021, took us only seven days before the first build of Python 3.11 appeared in the Fedora build system (Koji). Half a year and a couple of alpha releases after that, it took only three days to deliver the first beta release to users of Fedora Linux after the beta was released upstream.

If you are an early adopter, you probably know that it usually takes a few months before pre-release versions of Python appear in GitHub Actions, Travis CI, or other continuous integration (CI) providers. Fedora is generally much faster than those.

So in Fedora Linux, we have all you need to test your Python apps and libraries. But what if you are not a user of Fedora? Fedora-python-tox is here to help.

Going beyond Fedora

Fedora-python-tox is a container image based on the latest stable Fedora release, maintained by the same team of Python lovers at Fedora. In this container image, we combine all the aforementioned pieces (and some more bells and whistles) with compact packaging and release it on Docker Hub. The container image also contains a script that makes it very easy to use, whether the code you want to test is available on your local machine or in some remote version control repository.

There is one more important benefit. Suppose you develop applications or libraries for Fedora Linux, Red Hat Enterprise Linux, or others from the RPM family. In that case, you might need some specific RPM packages for your tests to run—for example, some library headers or Python bindings for dnf. The container image is prepared for that, and the only thing it needs is a list of RPM packages to install before the container executes tox. That's it.

And this is not the end. Last but not least, we provide a GitHub action named tox-github-action, which makes it even easier for you to integrate the solution in this article into your CI solution. If you use GitHub to develop apps or libraries for Fedora, there is no need to run your CI tests on Ubuntu anymore.

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