报错显示：

We're Unable to find the game "MsPacman". Note: Gym no longer distributes ROMs. If you own a license to use the necessary ROMs for research purposes you can download them via `pip install gym[accept-rom-license]`. Otherwise, you should try importing "MsPacman" via the command `ale-import-roms`. If you believe this is a mistake perhaps your copy of "MsPacman" is unsupported. To check if this is the case try providing the environment variable `PYTHONWARNINGS=default::ImportWarning:ale_py.roms`. For more information see: https://github.com/mgbellemare/Arcade-Learning-Environment#rom-management

解决方法：

在综合搜索之后，发现可行组合。值得一试

1.安装指定版本的gym和altari-py

pip install gym==0.19.0
pip install atari_py==0.2.6

 2.安装rom

官方参考：

https://github.com/openai/atari-py#roms

中文参考：

Exception: ROM is missing for ms_pacman, see https://github.com/openai/atari-py#roms for instruction_CSU_FuChou的博客-CSDN博客

测试代码：

import gym
#更换为所需的环境
env = gym.make("MsPacman-v0")
print(env.action_space.n)
env.render()
env.close()