Mesa: Agent-based modeling in Python

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Mesa allows users to quickly create agent-based models using built-in
core components (such as spatial grids and agent schedulers) or
customized implementations; visualize them using a browser-based
interface; and analyze their results using Python’s data analysis
tools. Its goal is to be the Python-based alternative to NetLogo,
Repast, or MASON.

Above: A Mesa implementation of the WolfSheep model, this
can be displayed in browser windows or Jupyter.

Features

• Modular components
• Browser-based visualization
• Built-in tools for analysis
• Example model library

Using Mesa

To install our latest stable release, run:

pip install -U mesa

Starting with Mesa 3.0, we don’t install all our dependencies anymore by default.

# You can customize the additional dependencies you need, if you want. Available are:
pip install -U mesa[network,viz]
# This is equivalent to our recommended dependencies:
pip install -U mesa[rec]
# To install all, including developer, dependencies:
pip install -U mesa[all]

You can also use pip to install the latest GitHub version:

pip install -U -e git+https://github.com/projectmesa/mesa@main#egg=mesa

Or any other (development) branch on this repo or your own fork:

pip install -U -e git+https://github.com/YOUR_FORK/mesa@YOUR_BRANCH#egg=mesa

Resources

For resources or help on using Mesa, check out the following:

• Intro to Mesa Tutorial (An introductory model, the Boltzmann
  Wealth Model, for beginners or those new to Mesa.)
• Visualization Tutorial (An introduction into our Solara visualization)
• Complexity Explorer Tutorial (An advanced-beginner model,
  SugarScape with Traders, with instructional videos)
• Mesa Examples (A repository of seminal ABMs using Mesa and
  examples of employing specific Mesa Features)
• Docs (Mesa’s documentation, API and useful snippets)
  • Development version docs (the latest version docs if you’re using a pre-release Mesa version)
• Discussions (GitHub threaded discussions about Mesa)
• Matrix Chat (Chat Forum via Matrix to talk about Mesa)

Running Mesa in Docker

You can run Mesa in a Docker container in a few ways.

If you are a Mesa developer, first install Docker
Compose and then, in the
folder containing the Mesa Git repository, you run:

$ docker compose up
# If you want to make it run in the background, you instead run
$ docker compose up -d

This runs the Schelling model, as an example.

With the docker-compose.yml file in this Git repository, the docker compose up command does two important things:

• It mounts the mesa root directory (relative to the
  docker-compose.yml file) into /opt/mesa and runs pip install -e on
  that directory so your changes to mesa should be reflected in the
  running container.
• It binds the docker container’s port 8765 to your host system’s
  port 8765 so you can interact with the running model as usual by
  visiting localhost:8765 on your browser

If you are a model developer that wants to run Mesa on a model, you need
to:

• make sure that your model folder is inside the folder containing the
  docker-compose.yml file
• change the MODEL_DIR variable in docker-compose.yml to point to
  the path of your model
• make sure that the model folder contains an app.py file

Then, you just need to run docker compose up -d to have it
accessible from localhost:8765.

Contributing to Mesa

Want to join the Mesa team or just curious about what is happening with
Mesa? You can...

• Join our Matrix chat room in which questions, issues, and
  ideas can be (informally) discussed.
• Come to a monthly dev session (you can find dev session times,
  agendas and notes on Mesa discussions).
• Just check out the code on GitHub.

If you run into an issue, please file a ticket for us to discuss. If
possible, follow up with a pull request.

If you would like to add a feature, please reach out via ticket or
join a dev session (see Mesa discussions). A feature is most likely
to be added if you build it!

Don’t forget to checkout the Contributors guide.

Citing Mesa

To cite Mesa in your publication, you can use the CITATION.bib.