This document discusses using Python with Neo4j. It provides an overview of Python libraries for Neo4j like Py2neo, neo4j-rest-client, and neo4jdb-python. It then demonstrates how to perform common graph operations like creating nodes and relationships, searching, modifying properties, deleting, and enforcing uniqueness using Py2neo. The document also mentions submitting Cypher queries and provides references for further reading.

1. Python and Neo4j
Eric Lee
Silicon Cloud International Pte Ltd
2015.DEC.17
@Singapore Neo4j Meetup

2. About Me
Eric Lee
NoSQL
Silicon Cloud
International
:Love
:EMPLOYEE_OF
Secured
Private Cloud
:PROVIDES
Neo4j
Cassandra
:IS
:IS
Python Perl JavaScript
:PROGRAMMING_IN
:PROGRAMMING_IN
:PROGRAMMING_IN

3. Start Your Neo4j Server
• Install Oracle JDK 8
• Download Neo4j Enterprise or Community edition
• Unzip it
• In Neo4j directory, execute this command:
./bin/neo4j start

4. Python Libraries for Neo4j
• Py2neo
Good performance for great amounts of nodes.
• neo4j-rest-client
If only a few nodes, use this REST based client.
• neo4jdb-python
Mainly for Cypher syntax manipulation.

5. Py2neo
• Installation
pip install py2neo

6. Authentication
• Before Neo4j 2.2
from py2neo import graph
graph = Graph()
Default is “http://127.0.0.1:7474/db/data”
• Neo4j 2.2/2.3, you need authentication
from py2neo import graph
graph = Graph(“http://neo4j:test@127.0.0.1:7474/db/data”)
Username Password

7. neo4j-server.properties
Uncomment this line for remote access
Replace “true” by “false” to disable authentication

8. Create Node
• Create node with label and properties
from py2neo import Graph, Node
graph = Graph(…)
Node1 = Node(“User”, Name=“Eric”, Gender=“M”)
graph.create(Node1)
Label Properties

9. Create Relationship
• One to one relationship
from py2neo import Graph, Node, Relationship
graph = Graph(…)
eric = Node(“User”, Name=“Eric”, Gender=“M”)
sci = Node(“Company”, Name=“Silicon Cloud Intl”)
ericWorkInsci = Relationship(eric,”WORK_IN”,sci,Since=2015)
graph.create(ericWorkInsci) Relationship Name Relationship Property
CREATE (User{Name:”Eric”…})-[:WORK_IN{Since:2015}]->(Company{Name:”Silicon Cloud Intl”})

10. Search
• Find One Node
graph.find_one(“User”,”Name”,”Eric”)
• Return all Nodes
results = graph.find(“User”, “Name”,”Eric”)
# will return an object
for result in results:
print result
Label Property Value

11. Modify Properties
• Add Property
eric = graph.find_one(“User”, “Name”, “Eric”)
eric.properties[“Surname”] = “Lee”
eric.push()

12. Delete
• Specific Objects
eric = graph.find_one(“User”, “Name”, “Eric”)
eric.delete()
• All nodes and relationships
graph.delete_all()
Easy than “MATCH (n)-[r]-(q) DELETE n,r,q”

13. Uniqueness
• Unique nodes
graph.schema.create_uniqueness_constraint("User", “Employee_ID”)
#Set the constraint first
eric = graph.merge_one(“User”, “Employee_ID”, “0007” )
• Unique Paths
eric = graph.merge_one(“User”, “Employee_ID”, “0007” )
mojy = graph.merge_one(“User”, “Employee_ID”, “0001” )
graph.create_unique(Relationship(mojy,”RECRUITS”,eric))

14. Submit Cypher Queries
• Submit qualified Cypher Syntax
graph.cypher.execute(cypher syntax string)
Return a list, to access each element, you can create a for loop.

15. Reference
• http://py2neo.org/2.0/intro.html
• http://www.slideshare.net/fphhotchips/a-quick-
review-of-python-and-graph-databases
• http://www.slideshare.net/leezhenyu/introduction-
to-graph-database