Add type annotations to three_dimensions.py

[henrikmidtiby]

Overview: What does this pull request change?

Motivation and Explanation: Why and how do your changes improve the library?

Links to added or changed documentation pages

Further Information and Comments

Reviewer Checklist

• The PR title is descriptive enough for the changelog, and the PR is labeled correctly
• If applicable: newly added non-private functions and classes have a docstring including a short summary and a PARAMETERS section
• If applicable: newly added functions and classes are tested

[chopan050]

Thanks for your contribution!

I left suggestions on the code. Most of them are minor changes, but there's a specific suggestion which is probably controversial and might require some discussion: making the checkerboard_colors None instead of False. Maybe it's better to simply use Literal[False] in this PR, discuss the topic, and then possibly change it to None in a follow-up PR?

[chopan050]

Thanks for your contribution!

I left suggestions on the code. Most of them are minor changes, but there's a specific suggestion which is probably controversial and might require some discussion: making the checkerboard_colors None instead of False. Maybe it's better to simply use Literal[False] in this PR, discuss the topic, and then possibly change it to None in a follow-up PR?

[henrikmidtiby]

I wonder what word is missing here ...

[henrikmidtiby]

Maybe it's better to simply use Literal[False] in this PR, discuss the topic, and then possibly change it to None in a follow-up PR?

I would prefer that approach. The changes are quite easy to make (see d5c54cf), but it would be nice to discuss this among the developers.