Gymnasium

It is the new version of Gym library.

Basic

It provides two things:

• An interface that allows you to create RL environments
• A collection of environments(gym-control, atari,box2D...)

With Gymnasium:

1. Create our environment using: gymnasium.make()
2. reset the environment to its initial state with observation = env.reset()

At each step:

1. Get an action using our model
2. Using env.step(action), we perform this acton in the environment and get
   • observation: The new state
   • reward: The reward
   • terminated: Indicates if the episode terminated
   • truncated: Indicates a timelimit or if an agent go out of bounds of the environment for instance
   • info: A dictionary that provides additional information(depend on the environment)

If the episode is terminated:

• we reset the environment to its initial state