BaseVectorEnv is not working when "lambda: gym.make(task) for _ in range(train_num)])"

[StevenJokess]

• [ ] I have marked all applicable categories:
  • [ ] exception-raising bug
  • [ ] RL algorithm bug
  • [x] documentation request (i.e. "X is missing from the documentation.")
  • [ ] new feature request
• [ ] I have visited the source website
• [ ] I have searched through the issue tracker for duplicates
• [ ] I have mentioned version numbers, operating system and environment, where applicable:

  import tianshou, torch, sys
  print(tianshou.__version__, torch.__version__, sys.version, sys.platform)

  I read https://tianshou.readthedocs.io/zh/latest/docs/5-example.html

https://github.com/thu-ml/tianshou/blob/master/tianshou/env/venvs.py https://github.com/StevenJokess/d2l-en-read/blob/moreme/RL/tianshou-DQN.ipynb

[Trinkle23897]

Sorry about that, I haven't updated this section. It is because we changed VectorEnv to DummyVectorEnv, and created an abstract class BaseVectorEnv to describe APIs. As you can see, BaseVectorEnv cannot work because all its methods are not implemented. I'll update it now. Thanks!

[StevenJokess]

If you use docs like http://preview.d2l.ai/d2l-en/master/chapter_linear-networks/softmax-regression-scratch.html, it will alarm you if you don't update.