ENH: Add lookup and putting of private elements

[naterichman]

Fairly simple lookup and adding of private tags with creator for InMemDicomObject as briefly discussed in #431

[Enet4]

Hey @naterichman, I made a quick code review, but it seems the branch also needs a rebase.

[naterichman]

I’ll rebase. I could have sworn I checkout from the master branch. I’m still getting used to contributing to a repo that’s not my own on GitHub (use gitlab for work)

Anyway I was thinking, regarding your comment about the attribute selector API on #431 . Do you want to keep methods like this and add supporting methods for the attribute selector API or would you be more interested in merging them into one single API for private tag access?

I was thinking we could expand the AttributeSelector enum to include a PrivateGroup and PrivateElement definition and these methods would take the corresponding selectors instead of group and element separately. LMK your thoughts

[Enet4]

I’ll rebase. I could have sworn I checkout from the master branch. I’m still getting used to contributing to a repo that’s not my own on GitHub (use gitlab for work)

It's OK, it's easy to miss the fact that one has to do both

1. fetch the latest contributions from the upstream remote: git fetch origin;
2. rebase against it in specific: git rebase origin/master instead of git rebase master unless the local master branch has also been updated.

Anyway I was thinking, regarding your comment about the attribute selector API on #431 . Do you want to keep methods like this and add supporting methods for the attribute selector API or would you be more interested in merging them into one single API for private tag access?

We can keep them separate. Each API usually stands on its own, meaning that one can do most of the things without the operations API. In other words, we can start with what we have in this PR, which is provide these methods to the in-mem DICOM object impl.

I was thinking we could expand the AttributeSelector enum to include a PrivateGroup and PrivateElement definition and these methods would take the corresponding selectors instead of group and element separately. LMK your thoughts

I'm not entirely sure how that would look like, but I suggest we defer to a separate PR. If #508 is cleaned up and made ready within the next day or two, it might just be ready in time for the upcoming major release.

[Enet4]

One more review iteration, mostly to emphasize that new parts of the public API should be documented, and to take care of clippy lints warnings that may emerge.

[naterichman]

Most of that is a big il’ facepalm. I’ll get this done today!

[Enet4]

Just added a few minor tweaks to the documentation in the last few commits.

The method signatures are good and the tests seem to cover the intended use cases well. Future work will hopefully tackle a more generalised awareness of private elements in the rest of the ecosystem, but it's great to have this PR as the first step towards it. Much appreciated! 👍