A wrapper is an environment transformation that takes in an environment as input, and outputs a new environment that is similar to the input environment, but with some transformation or validation applied.
The following wrappers can be used with PettingZoo environments:
PettingZoo Wrappers include conversion wrappers to convert between the AEC and Parallel APIs, and a set of simple utility wrappers which provide input validation and other convenient reusable logic.
Supersuit Wrappers include commonly used pre-processing functions such as frame-stacking and color reduction, compatible with both PettingZoo and Gymnasium.
Shimmy Compatibility Wrappers allow commonly used external reinforcement learning environments to be used with PettingZoo and Gymnasium.