Building Machine Learning Systems with Python - Third Edition

A small example

Anaconda doesn't ship this package, so it has to be installed though pip:

>>> pip install gym[atari]

We won't use the Atari part of the gym, but it will be required for the breakout game.

From this package, we can create an environment for different games, like this:

env = gym.make('FrozenLake-v0')

This creates a new environment for the text game FrozenLake. It consists of four four-character strings, starting with S and ending up at G, the goal. But there are holes (H) on the way to this goal, and ending up there makes you lose the game:

• SFFF
• FHFH
• FFFH
• HFFG

From the environment, we can get the size of the observation space, env.observation_space.n, which is 16 here (where the player is located) and the size of the action ...