Added type hints in utils package

[LetteraUnica]

Description

Type hinted all python modules under pettingzoo/utils. Pyright pre-commit checks were disabled on specific lines of code because they gave an error. More details in screenshots section.

When adding type hints I spotted some bugs, so I also edited some lines of code.

Type of change

Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality)

Screenshots

Error present even if we check attribute presence beforehand.

Same error but different way to check attribute presence. There are a few more errors like these, I won't show all of them here.

It says that action could be None, even if we perform a check at line 31.

In this case space is an instance of gymnasium.spaces.Space that does not have .low and .high attributes. However, we check in __init__ that the action spaces are Box spaces which in turn have the .low and .high attributes.

Checklist:

• I have run the pre-commit checks with pre-commit run --all-files (see CONTRIBUTING.md instructions to set it up)
• I have run pytest -v and no errors are present.
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I solved any possible warnings that pytest -v has generated that are related to my code to the best of my knowledge.
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[elliottower]

Finally got a chance to look this over a bit, thanks for helping out with this. I see there are a few TypeErrors to fix (https://github.com/Farama-Foundation/PettingZoo/actions/runs/4897571285/jobs/8745765176?pr=964):

 ERROR test/all_parameter_combs_test.py - TypeError: unsupported operand type(s) for |: 'type' and 'NoneType'
ERROR test/doc_examples_test.py - TypeError: unsupported operand type(s) for |: 'type' and 'NoneType'
ERROR test/pickle_test.py - TypeError: unsupported operand type(s) for |: 'type' and 'NoneType'
ERROR test/pytest_runner_test.py - TypeError: unsupported operand type(s) for |: 'type' and 'NoneType'
ERROR test/specific_env_test.py - TypeError: unsupported operand type(s) for |: 'type' and 'NoneType'
ERROR test/unwrapped_test.py - TypeError: unsupported operand type(s) for |: 'type' and 'NoneType'
ERROR test/variable_env_test.py - TypeError: unsupported operand type(s) for |: 'type' and 'NoneType'
!!!!!!!!!!!!!!!!!!! Interrupted: 7 errors during collection !!!!!!!!!!!!!!!!!!!!

[LetteraUnica]

Yeah I saw them, however they are only present in Python version <3.10, because all the tests for python 3.10 pass. Do you think I should substitute the | operator with Union?
For example, a: int | None -> a: Union[int, None]

[elliottower]

The | should work fine but you need to do from __futute__ import annotations I believe (in other files we use those and they work fine)

…

On Thu, May 11, 2023 at 10:49 AM Lorenzo Cavuoti ***@***.***> wrote: Yeah I saw them, however they are only present in Python version <3.10, because all the tests for python 3.10 pass. Do you think I should substitute the | operator with Union? For example, a: int | None -> a: Union[int, None] — Reply to this email directly, view it on GitHub <#964 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AHVPVA5LVUGJMRMBK4TDPQLXFT37ZANCNFSM6AAAAAAXXS3AA4> . You are receiving this because you commented.Message ID: ***@***.***>

[LetteraUnica]

I imported annotations in all files apart from clip_out_of_bounds_wrapper which caused the error. Pushed the changes and now it all seems ok.

I forgot to mention that I haven't added type hints to utils/conversions as I am not familiar with that part of the library and the code seems very complicated.

[elliottower]

Looks like all the comments are resolved, I’ll rise one final look through today but probably good to go. Would you mind making a separate PR changing the self state to be ndarray or any? Or I guess just any. I think I’ve seen something or any before as a way of suggesting but not enforcing

[LetteraUnica]

Just pushed the last changes, I think we can close this PR as well.

If I understand correctly, in subsequent PRs what remains to do is:

• Make env.state return Any.
• Where possible add assertions instead of ignoring pyright type errors.

Should I open an issue as a reminder? Because I don't think I'll have time to do this till next weekend.

[elliottower]

A few minor nitpicks but overall very good, thanks again for this it is very nice to have.