Split package into three ones: rotation, translation and transform_managers.

[szobov]

Hi there,
Thanks a lot for this amazing project. It's great!

I want to bring it to more widespread adoption and adopt it for internal projects.
But the showstopper I faced was that the project required some significant dependencies: "scipy", "lxml", "beautifulsoup4", which are used only in transform_manager's related code.

I think it can bring significant benefits if we split the project into three separated:

1. transformations, with dependencies: numpy and soft dependency matplotlib
2. rotations, with dependencies: numpy and soft dependency matplotlib
3. transform_managers: with dependencies: transformations, rotations and all other dependencies.

It will enable users to install required packages selectively if they don't need to use transform_managers.
If we agree on it, I can implement all required code changes.
I am eager to hear your opinion on it.

Thanks in advance,
Sergei

[AlexanderFabisch]

Hi @szobov ,

Thanks for your feedback!

You are right, there are too many non-optional dependencies right now. The code is written in a way that you should still be able to use most components without installing scipy or beautifulsoup4. A quick solution for the issue is to install it via pip with --no-deps and install numpy and matplotlib manually.

I'd like to avoid splitting the package into three separate packages. That would break a lot of existing code. I'd rather suggest making scipy and beautifulsoup4 optional dependencies and raise helfpful errors when an optional dependency is missing. I think the best solution would be to select an appropriate set of dependencies like this in pip:

pip install pytransform3d[transform_manager]
pip install pytransform3d[visualizer]
pip install pytransform3d[transform_manager,visualizer]

etc.

[AlexanderFabisch]

Here is the list of dependencies (including latest features that are under development):

required

• numpy

plotting

• matplotlib

plotting of meshes

• trimesh

visualizer

• open3d

transform_manager

• scipy

graph visualization

• pydot

urdf

• scipy
• beautifulsoup4
• lxml

jacobians

• scipy

uncertainty

• scipy

documentation

• numpydoc
• sphinx
• sphinx-gallery
• sphinx-bootstrap-theme

test

• pytest
• pytest-cov

[szobov]

Thanks for a quick reply @AlexanderFabisch !
Sure, we can do it this way.
If we agree on it, I can try to implement those changes.
What do you think?

[AlexanderFabisch]

Yes, that would be very helpful! I'd suggest to update the setup.py and documentation accordingly. Also maybe it is worth to take a look at how other Python packages manage their optional dependencies. pandas has lots of those for example. I'm happy to review any pull requests.

[AlexanderFabisch]

Release 3.0.0 is about to be released soon. Should this be part of it?

[szobov]

Release 3.0.0 is about to be released soon. Should this be part of it?

Hi @AlexanderFabisch ,
I'm sorry, but I got covid, and I don't think you should rely on me to wait for a release.
Another option could be if you'll let me know the planned date so I can estimate whether I can be on time.
I appreciate your understanding.

[AlexanderFabisch]

I won't release it before next week. Get well soon!

[szobov]

Hey @AlexanderFabisch
I'm sorry for the delayed reply.
I recently started working on the implementation.
I decided on implementing a pandas approach, but with a bit of a change to decouple version setting. (I was not happy with writing package names in many places)
I'll make a draft PR soon so that we can discuss it in review.
Thanks for your patience.

[AlexanderFabisch]

No worries, there is no time pressure :)