AttributeError: 'TraversalDescription' object has no attribute 'evaluator' - neo4j

Question

Im trying to traversal a graph using
from neo4jrestclient.client import GraphDatabase
G = GraphDatabase("http://localhost:7474/db/data/")
# G is generated here in my program but for space purpose I removed these steps
traverser = G.traversal().evaluator(my_evaluator).traverse(root)
I borrowed my_evaluator function from stackoverflow which is
def my_evaluator(path):
# Filter on end node property
if path.end['value'] == 105:
return Evaluation.INCLUDE_AND_CONTINUE
# Filter on last relationship type
if path.last_relationship.type.name() == 'edge':
return Evaluation.INCLUDE_AND_PRUNE
# You can do even more complex things here, like subtraversals.
return Evaluation.EXCLUDE_AND_CONTINUE
When I tried to execute the code I got the following error message:
Traceback (most recent call last):
File "C:\Users\firas\Desktop\ACO_neo4j.py", line 747, in
traverser = G.traversal().evaluator(my_evaluator).traverse(root)
AttributeError: 'TraversalDescription' object has no attribute 'evaluator'
Can you help me in this please. Thanks.
Firas

Answer 1

You can always use a Cypher query to to the same.
The problem here is that the evaluator funcion may be borrowed from the native driver by Neo4j guys, the embedded Python driver. So far, there is some limitations on traversing the graph using the neo4-rest-client traversals. Because underneath it is using the REST interface, the only way to write a evaluator is by writing a Javascript function, AFAIK.