Neo4j Python REST Client

synopsis:	Allows interact with Neo4j standalone REST server from Python.

The first objective of Neo4j Python REST Client is to make transparent for Python programmers the use of a local database through neo4j.py or a remote database thanks to Neo4j REST Server. So, the syntax of this API is fully compatible with neo4j.py. However, a new syntax is introduced in order to reach a more pythonic style.

The main file is named client.py, but you can rename with whatever you want.

Instantiation

The main class is GraphDatabase, exactly how in neo4j.py:

>>> from client import GraphDatabase

>>> gdb = GraphDatabase("http://localhost:9999")

By now, no options are provided.

Node, Relationships and Properties

Due to the syntax is fully compatible with neo4j.py, the next lines only show the commands added and its differences.

Creating a node:

>>> n = graphdb.node()

# Equivalent to
>>> n = graphdb.nodes.create()

Specify properties for new node:

>>> n = graphdb.node(color="Red", widht=16, height=32)

# Or
>>> n = graphdb.nodes.create(color="Red", widht=16, height=32)

Accessing node by id:

>>> n = graphdb.node[14]

# Using the identifier or the URL is possible too
>>> n = graphdb.nodes.get(14)

Accessing properties:

>>> value = n['key'] # Get property value

>>> n['key'] = value # Set property value

>>> del n['key']     # Remove property value

# Or the other way
>>> value = n.get('key', 'default') # Support 'default' values

>>> n.set('key', value)

>>> n.delete('key')

Besides, a Node object has other attributes:

>>> n.properties
{}

>>> n.properties = {'name': 'John'}
{'name': 'John'}

# The URL and the identifier assigned by Neo4j are added too
>>> n.id
14

>>> n.url
'http://localhost:9999/node/14'

Create relationship:

>>> n1.Knows(n2)

# Or
>>> n1.relationships.create("Knows", n2) # Usefull when the name of
                                         # relationship is stored in a variable

Specify properties for new relationships:

>>> n1.Knows(n2, since=123456789, introduced_at="Christmas party")

# It's the same to
>>> n1.relationships.create("Knows", n2, since=123456789,
                                         introduced_at="Christmas party")

The creation returns a Relationship object, which has properties, setter and getters like a node:

>>> rel = n1.relationships.create("Knows", n2, since=123456789)

>>> rel.start
<Neo4j Node: http://localhost:9999/node/14>

>>> rel.end
<Neo4j Node: http://localhost:9999/node/32>

>>> rel.type
'Knows'

>>> rel.properties
{'since': 123456789}

Others functions over 'relationships' attribute are possible. Like get all, incoming or outgoing relationships (typed or not):

>>> rels = n1.relationships.all()
[<Neo4j Relationship: http://localhost:9999/relationship/35843>,
 <Neo4j Relationship: http://localhost:9999/relationship/35840>,
 <Neo4j Relationship: http://localhost:9999/relationship/35841>,
 <Neo4j Relationship: http://localhost:9999/relationship/35842>,
 <Neo4j Relationship: http://localhost:9999/relationship/35847>,
 <Neo4j Relationship: http://localhost:9999/relationship/35846>,
 <Neo4j Relationship: http://localhost:9999/relationship/35845>,
 <Neo4j Relationship: http://localhost:9999/relationship/35844>,
 <Neo4j Relationship: http://localhost:9999/relationship/11>,
 <Neo4j Relationship: http://localhost:9999/relationship/10>,
 <Neo4j Relationship: http://localhost:9999/relationship/9>]

>>> rels = n1.relationships.incoming(types=["Knows"])
[<Neo4j Relationship: http://localhost:9999/relationship/35843>,
 <Neo4j Relationship: http://localhost:9999/relationship/35840>,
 <Neo4j Relationship: http://localhost:9999/relationship/11>,
 <Neo4j Relationship: http://localhost:9999/relationship/10>,
 <Neo4j Relationship: http://localhost:9999/relationship/9>]

>>> rels = n1.relationships.outgoing(["Knows", "Loves"])
[<Neo4j Relationship: http://localhost:9999/relationship/35842>,
 <Neo4j Relationship: http://localhost:9999/relationship/35847>]

Traversals

The traversals framework is supported too with the same syntax of neo4j.py, but with some added issues.

Regular way::

>>> n1.relationships.create("Knows", n2, since=1970)
<Neo4j Relationship: http://localhost:9999/relationship/36009>

>>> class TraversalClass(gdb.Traversal):
   ...:     types = [
   ...:         Undirected.Knows
   ...:     ]
   ...:

>>> [traversal for traversal in TraversalClass(n1)]
[<Neo4j Node: http://localhost:9999/node/15880>]

Added way (more ''pythonic'')::

>>> n1.relationships.create("Knows", n2, since=1970)
<Neo4j Relationship: http://localhost:9999/relationship/36009>

>>> n1.traverse(types=[client.Undirected.Knows])
[<Neo4j Node: http://localhost:9999/node/15880>]

Transaction

Currently, the transaction support is not implemented in Neo4j REST server, so the Python client is not able to provide it.