Transformer to prune graph

[Juliamg]

This implementation contains two new graph transformers means for pruning of a graph.

1. PruneDanglingNodes:
   Removes nodes from the graph that do not have any edges to any other nodes.

2. ResolveValues:
   Traverses the graph to find source nodes that point to other nodes with an edge to a value predicate. It then resolves this value directly to the source node, with the original predicate, so that the intermediate node can be skipped. Option to delete the intermediate node is present as well.

Used with the IODD extractor -

Graph summary before running these two transformers on the graph:

            Type  Occurrence
0     TextObject       166
1     IoddDevice           1
2  ProcessDataIn        1

Graph summary running ResolveValues:

ResolveValues(destination_node_type=IODD.TextObject, property_value=IODD.value).transform(graph)

            Type  Occurrence
0     TextObject         163
1     IoddDevice           1
2  ProcessDataIn           1

Graph summary after also running PruneDanglingNodes:

PruneDanglingNodes(node_prune_types=[IODD.TextObject]).transform(graph)

            Type  Occurrence
0     IoddDevice           1
1  ProcessDataIn         1

[github-actions]

☂️ Python Coverage

current status: ✅

Overall Coverage

Lines	Covered	Coverage	Threshold	Status
12751	8713	68%	60%	🟢

New Files

File	Coverage	Status
cognite/neat/graph/transformers/_iodd.py	0%	🟢
cognite/neat/graph/transformers/_prune_graph.py	0%	🟢
TOTAL	0%	🟢

Modified Files

File	Coverage	Status
cognite/neat/graph/extractors/_iodd.py	34%	🟢
TOTAL	34%	🟢

updated for commit: 2d57ce3 by action🐍

[nikokaoja]

Some changes of code requested

[nikokaoja]

you can do the same as suggested above and make customized PruneDanglingTextObjectNodes transformer

[nikokaoja]

but make sure to add attribute:

_use_only_once: bool = True
_need_changes = frozenset(
    {
        str(extractors.IODDExtractor.__name__),
        str(ResolveValues.__name__), 
    }
)

[nikokaoja]

What this transformer is doing is reducing:

sourceNode - [propertyX] -> destinatioNode -[propertyY] -> value
sourceNode - [propertyX] -> value

so you are reducing from 2 hops to get value to single hop, so maybe more descriptive name of method would be

FlattenDualHop

[nikokaoja]

ok I did not know you can access subject by stating this :) ! NICE!