Is there something like python setup.py --version for pyproject.toml?

Question

With a simple setup.py file:

from setuptools import setup
setup(
    name='foo',
    version='1.2.3',
)

I can do

$> python setup.py --version
1.2.3

without installing the package.

Is there similar functionality for the equivalent pyproject.toml file:

[project]
name = "foo"
version = "1.2.3"

Answer 1

With Python 3.11+, something like this should work:

python3.11 -c "import tomllib; print(tomllib.load(open('pyproject.toml', 'rb'))['project']['version'])"

This parses the TOML file directly, and assumes that version is not dynamic.

---

In some cases, version is declared dynamic in pyproject.toml, so it can not be parsed directly from this file and a solution (the only one?) is to actually build the project, or at least its metadata.

For this purpose, we can use the build.util.project_wheel_metadata() function from the build project, for example with a small script like this:

#!/usr/bin/env python

import argparse
import pathlib

import build.util

def _main():
    args_parser = argparse.ArgumentParser()
    args_parser.add_argument('path')
    args = args_parser.parse_args()
    path_name = getattr(args, 'path')
    path = pathlib.Path(path_name)
    #
    metadata = build.util.project_wheel_metadata(path)
    version = metadata.get('Version')
    print(version)

if __name__ == '__main__':
    _main()

Or as a one-liner:

python -c "import build.util; print(build.util.project_wheel_metadata('.').get('Version'))"