NotImplementedError: abstract

[Ljferrer]

Having trouble with gym.make().render()

I'm running Windows 10. This issue did not exist when I was working on python 3.6.3, but now that I downgraded to 3.5.2 for MuJoCo, this code (taken from another comment):

import gym
import random
import numpy as np
import tflearn
from tflearn.layers.core import input_data, dropout, fully_connected
from tflearn.layers.estimator import regression
from statistics import median, mean
from collections import Counter

LR = 1e-3
env = gym.make("CartPole-v0")
env.reset()
goal_steps = 500
score_requirement = 50
initial_games = 10000

def some_random_games_first():
    for episode in range(20):
        env.reset()
        for t in range(200):
            env.render()                        # if I comment out this line, everything runs fine
            action = env.action_space.sample()
            observation, reward, done, info = env.step(action)
            if done:
                break

some_random_games_first()

Produces this error:

Traceback (most recent call last):
File "C:\Users\LF\Documents\OpenAI Gym\CartPole\test.py", line 39, in
some_random_games_first()
File "C:\Users\LF\Documents\OpenAI Gym\CartPole\test.py", line 26, in some_random_games_first
env.render()
File "C:\Users\LF\Python35\lib\site-packages\gym\core.py", line 150, in render
return self._render(mode=mode, close=close)
File "C:\Users\LF\Python35\lib\site-packages\gym\core.py", line 286, in _render
return self.env.render(mode, close)
File "C:\Users\LF\Python35\lib\site-packages\gym\core.py", line 150, in render
return self._render(mode=mode, close=close)
File "C:\Users\LF\Python35\lib\site-packages\gym\envs\classic_control\cartpole.py", line 116, in render
self.viewer = rendering.Viewer(screen_width, screen_height)
File "C:\Users\LF\Python35\lib\site-packages\gym\envs\classic_control\rendering.py", line 51, in init
self.window = pyglet.window.Window(width=width, height=height, display=display)
File "C:\Users\LF\Python35\lib\site-packages\pyglet\window_init.py", line 504, in init
screen = display.get_default_screen()
File "C:\Users\LF\Python35\lib\site-packages\pyglet\canvas\base.py", line 73, in get_default_screen
return self.get_screens()[0]
File "C:\Users\LF\Python35\lib\site-packages\pyglet\canvas\base.py", line 65, in get_screens
raise NotImplementedError('abstract')
NotImplementedError: abstract

Also, pyglet is up to date (1.3.0)

I apologize if a solution can be found elsewhere, but I have not found another issue like this on gym.

[FirefoxMetzger]

I am by no means an expert with pyglet, so perhaps someone with more experience can help you better.

It looks like it can not open a window because it fails to find a display to render to.
Have you made sure you have an OpenGL install your python 3.5 can access? I know that you can use python-opengl on Ubuntu, but I am not sure if it is platform independent, but could be a place to start.

Another lead could be a bug in pyglet1.3rc1 . There are some folks that report running into the same error in a different context here and say it worked with pyglet 1.2.4

[Ljferrer]

Thank you for the response! Downgrading to pyglet 1.2.4 has solved the issue.

[FirefoxMetzger]

@Ljferrer Happy to help, if the problem is solved you can consider closing the issue to keep things nice and tidy =)

[akuchotrani]

@Ljferrer I was struggling from hours to fix the issue. Your comment really helped me fix the error. Thanks a lot!

[MikeDoho]

How do you downgrade? Sorry I am new to ubuntu....and just this in general haha.

[Ljferrer]

I believe the command is
pip install pyglet==1.2.4

[akuchotrani]

@MikeDoho Hey Mike, even I am not an expert. But I followed the following steps on windows(on anaconda cmd prompt). I hope it helps:-

1. Open commandline(anaconda cmd) and uninstall the current version of pyglet
   pip uninstall pyglet
2. Download the whl file of pyglet 1.2.4. If you are on python 3 select the py3 version
   link: https://pypi.python.org/pypi/pyglet/1.2.4
3. Copy this whl file into the location where python is installed I believe python/scripts
4. then copy the file name and open the command prompt and type
   pip install filename

Also if you are using any IDE like Spyder close the IDE and restart it again.
I hope it works.

Also there were some things just make sure that are installed. I had to install them.
1)Swig (if you want to run make any other environment except the cartpole)
2)Wheel

[MikeDoho]

Thank you everyone so much. I can see cartpole now.

[ylyhlh]

after some checking.
python3.6/site-packages/pyglet/__init__.py

change

if 'sphinx' in sys.modules:
    setattr(sys, 'is_epydoc', True)

to

if 'sphinx' in sys.modules:
    setattr(sys, 'is_epydoc', False)

pyglet has problem with jupyter, jupyter imports sphinx be default
but sphinx imported will lead pyglet thinks it is generating document? so cannot find display correctly.

[brindhasivash]

Downgrading to pyglet 1.2.4 worked for me. Thanks!

[wenjiaaa]

pyglet 1.2.4 worked for me ! Thanks a lot!