Add documentation for "bundling" python module(s)

[jcfr]

Related pull requests and issues:

• DOC: Describe how pip_install can be used in a module Slicer/Slicer#6913
• Improving Support for Python Package Dependencies in Slicer Extensions Slicer/Slicer#7171

[benzwick]

Is there a way to include/bundle python packages in a Slicer Custom App so that they don't need to be downloaded at run time (which is the suggested solution in the links above)?

[ebrahimebrahim]

Yes, in a custom app it can be done! I don't think this is necessarily the solutions linked above but here is an example where I recently did it:

• added this python dependencies project to the top level cmake: https://github.com/OpenwaterHealth/OpenLIFU-app/blob/main/CMakeLists.txt#L175
• added this cmake file to define the project: https://github.com/OpenwaterHealth/OpenLIFU-app/blob/main/SuperBuild%2FExternal_python-sliceropenlifu-requirements.cmake
  • Here you can see the pip install command referencing a requirements.txt file that is contained inside a slicer extension, but you could for example make it point to a file that is in your custom app repo