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neo4jpy2neo

Getting alphanumeric reference of nodes in py2neo, when looking for paths

I have a graph that consists of DATASET and GRAPH nodes. With the following relationships:

DATASET->READS->GRAPH

GRAPH->WRITES->DATASET

When I run the following : MATCH (p1:DATASET_NAME { name:'test1.dat' }),(p3:DATASET_NAME { name:'test32.txt' }), p = ((p1)-[:READS|:WRITES*1..8]->(p3)) RETURN p

In Neo4J Desktop I get a result that is correct, where node names are present. But when I run it in py2neo:

graph.run("MATCH (p1:DATASET_NAME { 
name:'test1.dat' }),(p3:DATASET_NAME { name:'test32.txt' }), p = ((p1)-[:READS|:WRITES*1..8]->(p3)) RETURN p").dump()

I get a result in the following format:

(f3ff862)-[:READS]->(c539bdc)-[:WRITES]->(b217f5a)-[:READS]->(ebf9c4f)-[:WRITES]->(f9ddd22)-[:READS]->(fcca016)-[:WRITES]->(a9c241a)
(f3ff862)-[:READS]->(c539bdc)-[:WRITES]->(b217f5a)-[:READS]->(ebf9c4f)-[:WRITES]->(f9ddd22)-[:READS]->(fcca016)-[:WRITES]->(e152f69)-[:READS]->(fcca016)-[:WRITES]->(a9c241a) (f3ff862)-[:READS]->(c539bdc)-[:WRITES]->(b217f5a)-[:READS]->(ebf9c4f)-[:WRITES]->(cbc5d42)-[:READS]->(fcca016)-[:WRITES]->(a9c241a)

I am assuming that these are some sort of references. Is there a way where I can get the string value for name from these references?

Solution

  • You are returning the matched path so what you see in py2neo is the representation of the path object. In the neo4j console it does a little extra looking up for you and presents the path as a set of nodes and relationships and it labels them according to what you have configured in the console.

    If you want to see the names in your py2neo output you could use the reduce function on the returned path p to produce a string with the node names and relationship types. Something like this should get you started. 

    MATCH (p1:DATASET_NAME { name:'test1.dat' }),(p3:DATASET_NAME { name:'test32.txt' }), p = ((p1)-[:READS|:WRITES*1..8]->(p3))
RETURN head(nodes(p)).name + ' - ' + reduce(path_str = "", r in relationships(p) | path_str + type(r) + ' - ' + endnode(r).name)

    In py2neo [Note the escape characters added in order to avoid cypher error. @ ...reduce(path_str = \"\"... ]:

    graph.run("MATCH (p1:DATASET_NAME { name:'/projects/bkrpty_vfcn/bkrpty_vfcn_vendr/data/serial/temp/yyyymmdd_yyyymmddhhmiss_bk_mrk_stat_init.dat' }),(p3:DATASET_NAME { name:'/projects/bkrpty_vfcn/bkrpty_vfcn_vendr/tables/onevgb1/ai_bkrpty_case' }), p = ((p1)-[:READS|:WRITES*1..8]->(p3)) RETURN head(nodes(p)).name + ' - ' + reduce(path_str = \"\", r in relationships(p) | path_str + type(r) + ' - ' + endnode(r).name)").dump()