Speedup, refactoring and modernization

[fjwillemsen]

Hi all! A while ago I implemented python-constraint in Kernel Tuner, an auto-tuning framework where we need to obtain all solutions on user-specified parameters and constraints before starting optimization. python-constraint works great, but it had some room for improvement, especially performance-wise.
I thus decided to fork python-constraint and make some changes, the following:

• Cythonized the package
• Added the OptimizedBacktracking solver based on issue #62
• Added type-hints to improve Cythonization
• Added the MaxProd and MinProd constraints
• Improved pre-processing for the MaxSum constraint
• Optimized the Function constraint
• Added getSolutionsOrderedList and getSolutionsAsListDict functions for efficient result shaping
• Overall optimization of common bottlenecks
• Split the codebase into multiple files for convenience
• Switched from setup.py to pyproject.toml
• Achieved and requires test coverage of at least 65%
• Added nox for local testing against all supported Python versions
• Added ruff for codestyle testing
• Dropped Python 3.4, 3.5, 3.6, 3.7 support

In all, this results in a huge speedup of >150x on a benchmark of 112 synthetic searchspaces:

I'd like to hear what the mainainers think about these changes and would be happy to see them integrated! Before releasing this, I think it would be a good idea to revise the package publishing process, and consider switching to GitHub Actions (I can help with this). If there are any questions, please let me know!

[scls19fr]

Hi @fjwillemsen

Very pleased to see such a contribution. I'm no longuer maintaining this repository. I sent you and invite to be member of https://github.com/python-constraint/ GH org and also grant you write access to https://github.com/python-constraint/python-constraint/
Feel free to take the lead on the project and improve it.
If you need something more just let me know.

Kind regards

Sébastien

[fjwillemsen]

@scls19fr thank you very much, I'll do my best :)
Perhaps it is not practical, but given that you will no longer maintain, could you make me owner instead of member? It appears I currently do not have access to the repository secrets, which prohibits a release on PyPI

[scls19fr]

Done.

[scls19fr]

https://pypi.org/project/python-constraint/ belongs to @niemeyer so I can't give you access.
You can either ask him or create a new PyPi project python-constraint2 or 3 for example.

[fjwillemsen]

Thank you! I have contacted @niemeyer via email, for continuity it would be ideal to keep it on the same package, I hope this will be possible.
Thank you very much for all of your contributions to python-constraint throughout the years!

[scls19fr]

Great work! Thanks @fjwillemsen
Renaming master branch to main should also be considered
https://github.com/github/renaming

[fjwillemsen]

Good suggestion! Renamed master branch to main

[fjwillemsen]

My emails to @niemeyer regarding PyPI access seem to go unanswered. @scls19fr could you perhaps get in touch with @niemeyer, or provide me with an alternative means of contact? My contact details are on my website.

[scls19fr]

what about a new name?
python-constraint2 or 3 or something else.
So we could be totally free.
I think it will be the simplest solution.

[fjwillemsen]

Yes, definitely, I had already created a python-constaint2 for beta testing. However, python-constraint had 148,000 downloads in the past month, which is a very solid user base I would prefer not to abandon if we have a choice.