I'm trying to run the following Cypher query in neomodel:
MATCH (b1:Bal { text:'flame' }), (b2:Bal { text:'candle' }),
p = shortestPath((b1)-[*..15]-(b2))
RETURN p
which works great on neo4j via the server console. It returns 3 nodes with two relationships connecting. However, when I attempt the following in python:
# Py2Neo version of cypher query in python
from py2neo import neo4j
graph_db = neo4j.GraphDatabaseService()
shortest_path_text = "MATCH (b1:Bal { text:'flame' }), (b2:Bal { text:'candle' }), p = shortestPath((b1)-[*..15]-(b2)) RETURN p"
results = neo4j.CypherQuery(graph_db, shortest_path_text).execute()
or
# neomodel version of cypher query in python
from neomodel import db
shortest_path_text = "MATCH (b1:Bal { text:'flame' }), (b2:Bal { text:'candle' }), p = shortestPath((b1)-[*..15]-(b2)) RETURN p"
results, meta = db.cypher_query(shortest_path_text)
both give the following error:
/Library/Python/2.7/site-packages/neomodel-1.0.1-py2.7.egg/neomodel/util.py in _hydrated(data)
73 elif obj_type == 'relationship':
74 return Rel(data)
---> 75 raise NotImplemented("Don't know how to inflate: " + repr(data))
76 elif neo4j.is_collection(data):
77 return type(data)([_hydrated(datum) for datum in data])
TypeError: 'NotImplementedType' object is not callable
which makes sense considering neomodel is based on py2neo.
The main question is how to get a shortestPath query to work via either of these? Is there a better method within python? or is cypher the best way to do it?
edit:
I also tried the following from here which gave the same error.
graph_db = neo4j.GraphDatabaseService()
query_string = "START beginning=node(1), end=node(4) \
MATCH p = shortestPath(beginning-[*..500]-end) \
RETURN p"
result = neo4j.CypherQuery(graph_db, query_string).execute()
for r in result:
print type(r) # r is a py2neo.util.Record object
print type(r.p) # p is a py2neo.neo4j.Path object
Ok, I figured it out. I used the tutorial [here]( based on @nigel-small 's answer.
from py2neo import cypher
session = cypher.Session("http://localhost:7474")
tx = session.create_transaction()
tx.append("START beginning=node(3), end=node(16) MATCH p = shortestPath(beginning-[*..500]-end) RETURN p")
tx.execute()
which returned:
[[Record(columns=(u'p',), values=(Path(Node('http://localhost:7474/db/data/node/3'), ('threads', {}), Node('http://localhost:7474/db/data/node/1'), ('threads', {}), Node('http://localhost:7474/db/data/node/2'), ('threads', {}), Node('http://localhost:7474/db/data/node/16')),))]]
From here, I expect I'll inflate each of the values back to my neomodel objects and into django for easier manipulation. Will post that code as I get there.