Gridenvs

Gridenvs is an open-source library that allows to easily create gym gridworld environments. To test some examples, run keyboard_agent.py.

Creating your own environments

You can easily create an environment by implementing the following three functions:

• get_init_state(): returns a dictionary containing the internal state of the environment. The state dict will contain all the necessary information of the game, and has to come with at least two elements: "world" (the GridWorld object) and "hero" (the agent GridObject).
• get_next_state(state, action): implements the logic of the environment, and returns a tuple (state, reward, end_of_episode, info) just as gym's env.step() function, except for the observation, that is automatically generated from the returned state.
• get_gridstate(state): returns a tuple consisting of the grid size and a list of objects to be rendered. This is used to generate the observation from the state.

Most environments consist of a single agent that moves in a grid (i.e. action affect a single object). If this is your case, consider inheriting from the HeroEnv class. To easily create a grid map, we provide a function that takes as input a list of strings, such as:

["WWWWWWWWWW",
 "WD.W....KW",
 "W..W.....W",
 "W..W..WWWW",
 "W........W",
 "W........W",
 "W..WWWW..W",
 "W........W",
 "WH.......W",
 "WWWWWWWWWW"]

See, for instance, the key-door examples.

To be able to create your environment with gym.make() you will need to register it. See gym's creating environments guide or check examples/__init__.py.

For other types of games, consider deriving directly from the Env class.

Installation

Clone the repository:

git clone https://github.com/aig-upf/gridenvs.git
cd gridenvs 

(Optional) If you want to create a virtual environment, you can do it by:

python3 -m venv my_venv
source my_venv/bin/activate

Install gridenvs:

pip3 install -r requirements.txt

When using it in other projects, make sure gridenvs is in your $PYTHONPATH (e.g. by adding it with export PYTHONPATH=\my\path\to\gridenvs).

If you are using an environment from the examples package, import it so that environments get registered to gym (i.e. import gridenvs.examples).