feat/group elements by parent_id

[ron-unstructured]

Is your feature request related to a problem? Please describe.
Following up with the document hierarchy implementation, it'll be helpful to have a built-in function to group elements with the same parent_id.

Describe the solution you'd like
Similar to chunk_by_title, but the parent type is not always a Title.

Describe alternatives you've considered
Group elements with the same parent_id and assign the previous element as the parent where parent_id is None.

Additional context
n/a

[dantes-ai]

Is there any news on that, or a work around to group chunks by parent id?

[qy2144]

The current chunk_by_title function does not retain parent-child relationship. Often a parent is grouped into previous chunk, even though itself is not a child of the previous chunk. Would like to see a new method that will respect parent/child relationship.

[weissenbacherpwc]

also looking for such a function.

[MthwRobinson]

If anyone is interested in picking this up as a first issue, I think it would make sense in unstructured/utils.py

[huangpan2507]

If anyone is interested in picking this up as a first issue, I think it would make sense in unstructured/utils.py

hi. @MthwRobinson , thanks for your information， do you mean it?

def is_parent_box(parent_target: Box, child_target: Box, add: float = 0.0) -> bool:
'''True if the child_target bounding box is nested in the parent_target.

Box format: [x_bottom_left, y_bottom_left, x_top_right, y_top_right].
The parameter 'add' is the pixel error tolerance for extra pixels outside the parent region'''

[KushagraaWadhwa]

Hi! I'd like to work on this issue. I'll implement a function to group elements by parent_id in unstructured/utils.py as suggested by @MthwRobinson. I'll make sure to handle cases where parent_id is None by grouping those elements with the previous element. Let me know if there are any specific requirements or edge cases I should consider!