Releasing Your Package

In this section we will describe how to take your package and publish a release to PyPI.

There are a lot of permutations on how to release your package, and depending on the size of your project you may need to build on this guide. The objective of this is to provide you with the basic information you need to release something built by following the rest of this guide.

This section of the guide is assuming you configured setuptools_scm in the Minimal package layout guide. If you didn’t you will need to update your pyproject.toml file as well as using git tag.

Incrementing Version Numbers

When you are ready to release your package you need to give it a version number. A version number for a release should generally be of the form X.Y.Z, for full details on versioning Python packages see PEP 440. What meaning is conveyed by the version numbers is up to you, there are multiple different thoughts on this, for some examples see Astropy, SunPy or Semantic Versioning.

In this example we are going to release version 0.1.0 of our package my_package. When doing releases it is common practice to use git tags to identify the commit the release relates to in the history. By using setuptools_scm these tags become the reference for the version numbers of your Python package. This means you only have to increment your version number using git.

To mark a new release of your package in your git history run:

$ git tag -a v0.1.0 -m "Release version 0.1.0"

Here we use the convention of prepending release tags with v.

If you now import your package and print my_package.__version__ it should say 0.1.0.

Building Source Distributions

Now you have tagged your release, you need to build what is called a “source distribution” to upload to PyPI or the Python Package Index. This is the place where tools like pip download packages from and is the primary place people will search for installable Python packages.

The source distribution is a tarball of all the files needed by your package, which includes everything in your my_package directory as well as everything specified in your file.

As we have setup a package with a pyproject.toml file, we recommend you use the build package to build your source distribution in the isolated environment specified in pyproject.toml. You can do this with:

$ pip install build
$ python -m build --sdist --outdir dist .

This is equivalent to running the legacy python sdist but ensures that the state of your local environment does not affect the generated package.

Publishing to PyPI

Now you have created the sdist to be uploaded to PyPI you can upload it with the twine package:

$ pip install twine
$ twine upload dist/my_package*.tar.gz

This should ask you for your PyPI account details, and will create your project on PyPI if it doesn’t already exist.

Releasing from Branches

If your project is larger, you might want to create branches for each of your major release versions to make it easy to continue to support those releases with bug fixes while continuing development of your master branch.

If you follow this pattern for your releases you will have to perform one extra step when using setuptools_scm, which is to also increment the version with a tag on the master branch to indicate you have started to develop a new version on your master branch. To do this at the point where you branch for your upcoming release push a tag for vX.Ydev where X.Y is the version number of the next major release e.g. if you just branched for 1.1 you would create a v1.2dev tag.