v3.1.0

Highlights

With Mesa 3.1.0 we're back on our regular release schedule after the big Mesa 3.0 release, with some exciting new features.

This release adds experimental support for Observables and Computed, enabling a more reactive and responsive programming model for agent-based simulations. The new Observable and Computable classes allow developers to declaratively define attributes that automatically emit signals when their values change, and compute derived values that update dynamically. This lays the groundwork for more advanced event handling and data visualization features in future releases (#2291).

The experimental cell space module has been updated with full support for n-dimensional property layers. These allow agents to easily interact with and modify spatial properties of the environment, such as terrain, resources, or environmental conditions. The new implementation provides a more intuitive attribute-based API and ensures tight integration with the cell space architecture (#2512).

Mesa now includes built-in support for logging using the standard Python logging module. This provides developers with a flexible and powerful way to add structured diagnostic and debug output to their simulations, without the need for custom logging solutions. The logging system is integrated throughout the library, including the new SolaraViz visualization system (#2506).

Creating multiple agents with varying initialization parameters is now significantly easier with the new Agent.create_agents class method. This factory function supports both uniform and per-agent parameters, simplifying the code required to set up a simulation with a large number of heterogeneous agents (#2351).

In addition to the major new features, this release includes a number of smaller enhancements and bug fixes that improve the overall developer experience. These include removing deprecated functionality, cleaning up examples, and addressing various edge cases reported by the community. Mesa 3.1 requires Python 3.11 or higher.

What's Changed

🧪 Experimental features

• Add support for Observables to MESA by @quaquel in #2291
• Add full support for property layers to cell spaces by @quaquel in #2512

🎉 New features added

• Add logging to MESA by @quaquel in #2506
• Add create_agents factory method to Agent by @quaquel in #2351

🔍 Examples updated

• Add seed control to all examples by @quaquel in #2496

📜 Documentation improvements

• doc fix for pip install error on mac by @quaquel in #2508
• Refactored docs for Introductory Tutorial by @Spartan-71 in #2511
• Add module-level docstring to experimental features by @EwoutH in #2532

🔧 Maintenance

• Remove deprecated time module by @EwoutH in #2476
• Drop support for Python 3.10, require Python >= 3.11 by @EwoutH in #2474
• Remove deprecated functionality by @EwoutH in #2483
• Remove visualization modules from mesa.experimental by @quaquel in #2495
• Cleanup two occurrences of removed scheduler by @EwoutH in #2499
• move _setup_agent_registration into Model.__init__ by @quaquel in #2501
• remove devs related examples from devs/examples by @quaquel in #2507
• added empty iterable checks and updated tests by @Sahil-Chhoker in #2523
• Fix: running Mesa in Docker with Schelling model by @AdamZh0u in #2524

New Contributors

• @Spartan-71 made their first contribution in #2511
• @Sahil-Chhoker made their first contribution in #2523
• @AdamZh0u made their first contribution in #2524

Full Changelog: v3.0.3...v3.1.0