projectmesa/mesa: v2.3.0

Highlights

Mesa 2.3.0 is a big feature release and the last feature release before 3.0.

There are two main new features:

• The experimental cell-centric discrete spaces, as added in #1994. It allows having cells with not only properties but also active behaviors: the CellAgent. Its inspired by NetLogo's patches but extend and generalize this concept further.
• Full support for discrete event scheduling, as added in #2066. It allows scheduling events (like Agent actions) at any time, including non-integer timesteps.

There are a lot of other features: The Jupyter visualisation now supports easier way to specify sliders, NetworkGrid.get_neighbors() supports a radius, AgentSet.get() can retrieve multiple attributes and there are now benchmarks to track Mesa performance during development.

Finally, 2.3.0 stabilizes the AgentSet (including model.agents), making it the first experimental Mesa feature that is taken out of it's experimental phase.

Install this release with:

pip install --upgrade mesa

The Mesa 2.3.x-series supports Python 3.9 to 3.12. The next major release will require Python 3.10.

What's Changed

🧪 Experimental features

• Add cell-centric discrete spaces (experimental) by @Corvince in https://github.com/projectmesa/mesa/pull/1994

🎉 New features added

• Add performance benchmarking scripts by @EwoutH in https://github.com/projectmesa/mesa/pull/1979
• feat: Implement Slider class for JupyterViz by @rht in https://github.com/projectmesa/mesa/pull/1972
• Stabilize AgentSet by @EwoutH in https://github.com/projectmesa/mesa/pull/2065
• Support discrete event scheduling by @quaquel in https://github.com/projectmesa/mesa/pull/2066

🛠 Enhancements made

• JupyterViz: Automatically deduce display name from model class by @rht in https://github.com/projectmesa/mesa/pull/1975
• Add radius argument to NetworkGrid.get_neighbors() by @EwoutH in https://github.com/projectmesa/mesa/pull/1973
• Speedup of Agentset.shuffle by @quaquel in https://github.com/projectmesa/mesa/pull/2010
• feat: Let mesa runserver detect server.py as fallback by @rht in https://github.com/projectmesa/mesa/pull/2015
• JupyterViz: {Convert make_plot & prepare ColorCard} to become Solara component by @rht in https://github.com/projectmesa/mesa/pull/2020
• new feature: AgentSet.get can retrieve one or more then one attribute by @quaquel in https://github.com/projectmesa/mesa/pull/2044
• Update CODE_OF_CONDUCT.md to version 2+ of contrib covenant by @jackiekazil in https://github.com/projectmesa/mesa/pull/2052
• Improve flocking benchmark by @coderbeta1 in https://github.com/projectmesa/mesa/pull/2054
• Remove JupyterViz Altair marker overlap for huge grid size by @rht in https://github.com/projectmesa/mesa/pull/2062
• Add tooltip option to Altair chart by @FoFFolo in https://github.com/projectmesa/mesa/pull/2082
• feat: Display model seed & allow user to specify it in JupyterViz by @rht in https://github.com/projectmesa/mesa/pull/2069
• warn if placing already placed agent by @puer-robustus in https://github.com/projectmesa/mesa/pull/2083

🐛 Bugs fixed

• fix: Apply default value to slider by @rht in https://github.com/projectmesa/mesa/pull/2016
• fix: Initialize model _steps and _time during new by @rht in https://github.com/projectmesa/mesa/pull/2026
• fix: Use model.schedule only when it is not None by @rht in https://github.com/projectmesa/mesa/pull/2050
• fix: Remove JupyterViz grid marker overlap for huge grid size by @rht in https://github.com/projectmesa/mesa/pull/2049
• Make agent move to actual random closest position by @EwoutH in https://github.com/projectmesa/mesa/pull/2119

📜 Documentation improvements

• Improve readability of badges by @rht in https://github.com/projectmesa/mesa/pull/2009
• More pythonic implementation of wolf sheep by @quaquel in https://github.com/projectmesa/mesa/pull/2011
• Adding super().init() to MoneyModel tutorial by @sw23 in https://github.com/projectmesa/mesa/pull/2025
• docs: Convert howto.rst -> howto.md via rst2myst by @rht in https://github.com/projectmesa/mesa/pull/2033
• docs: Convert best-practices,overview,packages,mesa,index to .md via rst2myst by @rht in https://github.com/projectmesa/mesa/pull/2034
• docs: Convert api/.rst -> api/.md via rst2myst by @rht in https://github.com/projectmesa/mesa/pull/2035
• docs: Rewrite howto.md using ChatGPT for clarity and conciseness by @rht in https://github.com/projectmesa/mesa/pull/2037
• docs: Corrected Contributing Guide Link to Ensure Accessibility by @sahusiddharth in https://github.com/projectmesa/mesa/pull/2057
• Rename links to internal .rst files to .md by @rht in https://github.com/projectmesa/mesa/pull/2058
• docs: improve introductory tutorial by @puer-robustus in https://github.com/projectmesa/mesa/pull/2087

🔧 Maintenance

• Quality of Life: Make codecov less meticulous by @Corvince in https://github.com/projectmesa/mesa/pull/1966
• Add CI workflow for performance benchmarks by @EwoutH in https://github.com/projectmesa/mesa/pull/1983
• tests: Resolve warnings by defining PropertyLayer dtypes by @EwoutH in https://github.com/projectmesa/mesa/pull/1987
• benchmarks.yml: Fix PR branch checkout when triggered by comment by @EwoutH in https://github.com/projectmesa/mesa/pull/1998
• Quality of life: automatically fix ruff errors by @Corvince in https://github.com/projectmesa/mesa/pull/2004
• benchmarks.yml: Run on addition of label instead of comment by @EwoutH in https://github.com/projectmesa/mesa/pull/2002
• ci: Move codespell to pre-commit by @rht in https://github.com/projectmesa/mesa/pull/2040
• Schelling by @coderbeta1 in https://github.com/projectmesa/mesa/pull/2053
• Move ruff lint settings into dedicated section by @Corvince in https://github.com/projectmesa/mesa/pull/2073
• ci: Use uv pip for faster build by @rht in https://github.com/projectmesa/mesa/pull/2038
• test: Remove place_agent duplicate warnings by @rht in https://github.com/projectmesa/mesa/pull/2086

Other changes

• Minor edits to benchmarking code by @quaquel in https://github.com/projectmesa/mesa/pull/1985
• build(deps): bump codecov/codecov-action from 3 to 4 by @dependabot in https://github.com/projectmesa/mesa/pull/2030
• [pre-commit.ci] pre-commit autoupdate by @pre-commit-ci in https://github.com/projectmesa/mesa/pull/2029
• tests: Speed up test_batch_run by @rht in https://github.com/projectmesa/mesa/pull/2039
• Update benchmarks.yml by @Corvince in https://github.com/projectmesa/mesa/pull/2043
• docs: Convert visualization .rst -> .md via rst2myst by @rht in https://github.com/projectmesa/mesa/pull/2036
• docs: Convert CONTRIBUTING .rst -> .md via rst2myst by @rht in https://github.com/projectmesa/mesa/pull/2041
• Correct wolf energy gained from eating sheep by @JackAtOmenApps in https://github.com/projectmesa/mesa/pull/2048
• feat: Implement Altair version of grid visualization by @rht in https://github.com/projectmesa/mesa/pull/1991

New Contributors

• @sw23 made their first contribution in https://github.com/projectmesa/mesa/pull/2025
• @JackAtOmenApps made their first contribution in https://github.com/projectmesa/mesa/pull/2048
• @coderbeta1 made their first contribution in https://github.com/projectmesa/mesa/pull/2054
• @sahusiddharth made their first contribution in https://github.com/projectmesa/mesa/pull/2057
• @FoFFolo made their first contribution in https://github.com/projectmesa/mesa/pull/2082
• @puer-robustus made their first contribution in https://github.com/projectmesa/mesa/pull/2083

Full Changelog: https://github.com/projectmesa/mesa/compare/v2.2.4...2.3.0