Gym-Notebook-Wrapper

Gym-Notebook-Wrapper provides small wrappers for running and rendering OpenAI Gym on Jupyter Notebook or similar (e.g. Google Colab).

1. Requirement

• Linux
• Xvfb
  • On Ubuntu, you can install sudo apt update && sudo apt install xvfb.
• Open GL (for some environment)
  • On Ubuntu, you can install sudo apt update && sudo apt install python-opengl

2. Installation

You can install from PyPI with pip install gym-notebook-wrapper

3. Usage

Three classes are implemented in gnwrapper module in this gym-notebook-wrapper package.

3.1 Simple One Shot Animation

Wrap gym.Env class with gnwrapper.Animation. That's all! The render() method shows the environment on its output. An example code is following;

3.1.1 Code

import gnwrapper
import gym

env = gnwrapper.Animation(gym.make('CartPole-v1'))

obs = env.reset()

for _ in range(1000):
    next_obs, reward, done, info = env.step(env.action_space.sample())
    env.render()

    obs = next_obs
    if done:
        obs = env.reset()

3.1.2 Limitation

• Calling render() method delete the other output for the same cell.
• The output image is shown only once.

3.2 Loop Animation

Wrap gym.Env class with gnwrapper.LoopAnimation. This wrapper stores display image when render() methos is called and shows the loop animation by display(dpi=72,interval=50) methos.

3.2.1 Code

import gnwrapper
import gym

env = gnwrapper.LoopAnimation(gym.make('CartPole-v1'))

obs = env.reset()

for _ in range(100):
    next_obs, reward, done, info = env.step(env.action_space.sample())
    env.render()

    obs = next_obs
    if done:
        obs = env.reset()

env.display()

3.2.2 Limitation

• Require a lot of memory to store and display large steps of display
  • Can raise memory error

3.3 Movie Animation

Wrap gum.Env class with gnwrapper.Monitor. This wrapper inherits gym.wrappers.Monitor and implements display() method for embedding mp4 movie into Notebook.

If you call display(reset=True), the video list is cleared and the next display() method shows only new videos.

3.3.1 Code

import gnwrapper
import gym

env = gnwrapper.Monitor(gym.make('CartPole-v1'),directory="./")

o = env.reset()

for _ in range(100):
    o, r, d, i = env.step(env.action_space.sample())
    if d:
        env.reset()

env.display()

3.3.2 Limitation

• Require disk space for save movie

4. Notes

gnwrapper.Animation and gnwrapper.LoopAnimation inherit from gym.Wrapper, so that it can access any fields or mothods of gym.Env and gym.Wrapper (e.g. action_space).

5. Links

• Repository
• GitHub Mirror