openAI Gym NameError in Google Colaboratory

Question

I've just installed openAI gym on Google Colab, but when I try to run 'CartPole-v0' environment as explained here.

Code:

import gym
env = gym.make('CartPole-v0')
for i_episode in range(20):
    observation = env.reset()
    for t in range(100):
        env.render()
        print(observation)
        action = env.action_space.sample()
        observation, reward, done, info = env.step(action)
        if done:
            print("Episode finished after {} timesteps".format(t+1))
            break

I get this:

WARN: gym.spaces.Box autodetected dtype as <class 'numpy.float32'>. Please provide explicit dtype.
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
<ipython-input-19-a81cbed23ce4> in <module>()
      4     observation = env.reset()
      5     for t in range(100):
----> 6         env.render()
      7         print(observation)
      8         action = env.action_space.sample()

/content/gym/gym/core.py in render(self, mode)
    282 
    283     def render(self, mode='human'):
--> 284         return self.env.render(mode)
    285 
    286     def close(self):

/content/gym/gym/envs/classic_control/cartpole.py in render(self, mode)
    104 
    105         if self.viewer is None:
--> 106             from gym.envs.classic_control import rendering
    107             self.viewer = rendering.Viewer(screen_width, screen_height)
    108             l,r,t,b = -cartwidth/2, cartwidth/2, cartheight/2, -cartheight/2

/content/gym/gym/envs/classic_control/rendering.py in <module>()
     21 
     22 try:
---> 23     from pyglet.gl import *
     24 except ImportError as e:
     25     reraise(prefix="Error occured while running `from pyglet.gl import *`",suffix="HINT: make sure you have OpenGL install. On Ubuntu, you can run 'apt-get install python-opengl'. If you're running on a server, you may need a virtual frame buffer; something like this should work: 'xvfb-run -s \"-screen 0 1400x900x24\" python <your_script.py>'")

/usr/local/lib/python3.6/dist-packages/pyglet/gl/__init__.py in <module>()
    225     else:
    226         from .carbon import CarbonConfig as Config
--> 227 del base
    228 
    229 # XXX remove

NameError: name 'base' is not defined

The problem is the same in this question about NameError in openAI gym

Nothing is being rendered. I don't know how I could use this in google colab: 'xvfb-run -s \"-screen 0 1400x900x24\" python <your_script.py>'"

Solution 1

The Gym will normally render the display using GL, on your screen.

But Colab is run on the web as a notebook, it can’t display directly to your screen. It can only show the result through HTML.

If someone modifies the Gym to maniplulate WebGL, maybe someday. But not now.

Solution 2

One way to render gym environment in google colab is to use pyvirtualdisplay and store rgb frame array while running environment. Environment frames can be animated using animation feature of matplotlib and HTML function used for Ipython display module. You can find the implementation here. Make sure you install required libraries which you can find in the first cell of the colab. In case the first link for google colab doesn't work you can see this one.

Solution 3

i saw an suitablbe answer here.

pip install pyglet==1.5.11

Comments

[Javier A. Zambrano Macias]

Thank you Korakot. We still have to wait!

[Javier A. Zambrano Macias]

Hi! Not at the moment. I think Korakot is right, Gym should be modified to manipulate webGL and then we would be able to see our algorithm in action. I' ve been thinking of training an algorithm without calling env.render() and try to use the monitor to generate a video file of the experience. What do you think about that?

[user650585]

Hi. Well I just tried it without calling render and it seems to be working. But since I am very new to gym environment, when it comes to recording and playing it back , are you talking about the playback section in this page: github.com/openai/retro?

[Javier A. Zambrano Macias]

Hi, I am talking about something like this discuss.openai.com/t/way-to-train-without-opening-a-window/1‌​188

[Javier A. Zambrano Macias]

I am not sure if what is explained in the playback section is the same. Have you tried it to?

[NegatioN]

Super helpful. Until we get WebGL rendering, this is definitely the way to go for anyone stumbling in here.

[Krishna]

@Yograj It's working fine. But can you add few other lines of code that install Box2D too. CartPole is running fine on it but when I use CarRacing it throws error. I tried installing Box2D from various sources, but failed all the time.

[Dhia Hassen]

This is not an answer , it is a comment , or rather a question

[Johannes Ackermann]

@सत्यमेवजयते Did you happen to figure out a solution for the box2 environments?

[Krishna]

I don't exactly remember, how I did it. Good luck finding it.

[elexhobby]

Sorry, the file you have requested does not exist.