Automatic version number both in setup.py (setuptools) AND source code?

Question

SITUATION:

I have a python library, which is controlled by git, and bundled with distutils/setuptools. And I want to automatically generate version number based on git tags, both for setup.py sdist and alike commands, and for the library itself.

For the first task I can use git describe or alike solutions (see How can I get the version defined in setup.py (setuptools) in my package?).

And when, for example, I am in a tag '0.1' and call for 'setup.py sdist', I get 'mylib-0.1.tar.gz'; or 'mylib-0.1-3-abcd.tar.gz' if I altered the code after tagging. This is fine.

THE PROBLEM IS:

The problem comes when I want to have this version number available for the library itself, so it could send it in User-Agent HTTP header as 'mylib/0.1-3-adcd'.

If I add setup.py version command as in How can I get the version defined in setup.py (setuptools) in my package?, then this version.py is generated AFTER the tag is made, since it uses the tag as a value. But in this case I need to make one more commit after the version tag is made to make the code consistent. Which, in turns, requires a new tag for further bundling.

THE QUESTION IS:

How to break this circle of dependencies (generate-commit-tag-generate-commit-tag-...)?

Answer 1

You could also reverse the dependency: put the version in mylib/__init__.py, parse that file in setup.py to get the version parameter, and use git tag $(setup.py --version) on the command line to create your tag.

git tag -a v$(python setup.py --version) -m 'description of version'

Is there anything more complicated you want to do that I haven’t understood?