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>'"
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.