NotImplementedError when executing Pong example

Hey guys, first of all thanks a lot for this project. It might become handy during my studies 😃

I ran into an error while executing the example. I downloaded the pretrained model, but python3 -m baselines.deepq.experiments.atari.enjoy --model-dir /tmp/models/model-atari-duel-pong-1 --env Pong --dueling raised the following error:

[2018-01-31 12:24:50,221] Making new env: PongNoFrameskip-v4
Traceback (most recent call last):
  File "/usr/lib/python3.4/runpy.py", line 170, in _run_module_as_main
    "__main__", mod_spec)
  File "/usr/lib/python3.4/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "/home/username/keras-tf-p3/baselines/baselines/deepq/experiments/atari/enjoy.py", line 70, in <module>
    play(env, act, args.stochastic, args.video)
  File "/home/username/keras-tf-p3/baselines/baselines/deepq/experiments/atari/enjoy.py", line 43, in play
    obs = env.reset()
  File "/home/username/keras-tf-p3/baselines/baselines/common/atari_wrappers.py", line 167, in reset
    ob = self.env.reset()
  File "/home/username/keras-tf-p3/lib/python3.4/site-packages/gym/core.py", line 104, in reset
    return self._reset()
  File "/home/username/keras-tf-p3/lib/python3.4/site-packages/gym/core.py", line 283, in _reset
    return self.env.reset()
  File "/home/username/keras-tf-p3/lib/python3.4/site-packages/gym/core.py", line 104, in reset
    return self._reset()
  File "/home/username/keras-tf-p3/lib/python3.4/site-packages/gym/core.py", line 310, in _reset
    observation = self.env.reset()
  File "/home/username/keras-tf-p3/lib/python3.4/site-packages/gym/core.py", line 104, in reset
    return self._reset()
  File "/home/username/keras-tf-p3/lib/python3.4/site-packages/gym/core.py", line 311, in _reset
    return self._observation(observation)
  File "/home/username/keras-tf-p3/lib/python3.4/site-packages/gym/core.py", line 321, in _observation
    raise NotImplementedError
NotImplementedError

The cartpole example however works fine (python -m baselines.deepq.experiments.train_cartpole)

I found this issue in gym (https://github.com/openai/gym/issues/775) with the same error message, but mine seems to occur in reset() and not in render(). Downgrading to pyglet version 1.2.4 as suggested did not change anything.

Does someone know a solution to this?

[hudsontek]

It may be a version-conflict problem. Upgrading the gym or Downgrading can solve it.

In my case, downgrading from 0.18 to 0.10 solved the problem.

[NoobHua]

It may be a version-conflict problem. Upgrading the gym or Downgrading can solve it.