ImportError: cannot import name 'FlattenObservation'

[SHYang1210]

After I installed it according to the requirements, I got an ImportError: cannot import name 'FlattenObservation' error. I know that it is the version of the gym package or something went wrong elsewhere. Thanks for the help!
File "/home/xxx/baselines/baselines/run.py", line 12, in
from baselines.common.cmd_util import common_arg_parser, parse_unknown_args, make_vec_env, make_env
File "/home/xxx/baselines/baselines/common/cmd_util.py", line 12, in
from gym.wrappers import FlattenObservation, FilterObservation
ImportError: cannot import name 'FlattenObservation'

[MatPoliquin]

pip3 show gym
What version do you see?

I got the same error, you can fix it by installing 0.15.4:
pip3 install gym==0.15.4

[yemam3]

I'm getting the same issue and my gym version is 0.15.4... any other recommended fixes?

[ryanmaxwell96]

I am also getting the same issue with 0.15.4. Any help?

[ryanmaxwell96]

So I'm not sure if this is the answer, but upon looking into the gym/gym/wrappers, folder, it looks like there are only files named "flatten_ovservation" and "filter_observation" so I just chose to import the entire wrappers folder with:

from gym import wrappers

in the cmd_util.py file to get beyond this error. Of course now I get a new error though:
File "baselines/common/retro_wrappers.py", line 202
def make_retro(*, game, state=None, max_episode_steps=4500, **kwargs):
^
SyntaxError: invalid syntax

[SHYang1210]

9ee399f
Check your gym version first, the package is modified after 0.15.4, you can check the link above, you can reduce your gym version, use the previous package

[ryanmaxwell96]

So what if we have 0.15.4 already? go even earlier?

[ryanmaxwell96]

I was finally able to get it to work, though with gym 0.15.3 not 0.15.4. Also, I had to remove two underscores in the run.py.