Introduction to PettingZoo

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This work has been translated from Korean to English using Claude 4.5 Sonnet.

Documentation link

PettingZoo Documentation

Brief Introduction to PettingZoo

PettingZoo is a Python library that facilitates General Multi-Agent Reinforcement Learning (MARL) simulations.

PettingZoo consists of two main APIs:

• AEC API: Helps implement environments with turns between agents, similar to board games.
  • Environments with turns are called Agent Environment Cycle (AEC) environments.
• Parallel API: All agents act simultaneously within a single time step.
  • These are called Parallel environments, referring to parallel/concurrent execution.

There exist AEC-to-Parallel and Parallel-to-AEC converters that allow transformation between the two APIs. However, when developing for the first time, it’s recommended to focus on one API without worrying too much about conversion.