pyley
Python client for an open-source graph database Cayley
Cayley is an open-source graph inspired by the graph database behind Freebase and Google's Knowledge Graph. Its goal is to be a part of the developer's toolbox where Linked Data and graph-shaped data (semantic webs, social networks, etc) in general are concerned.
Install via pip
pip install pycayley
Sample
#Create cayley client
client = CayleyClient() # this creates client with default parameters `http://localhost:64210/api/v1/query/gremlin`
#or specify `url` and `version` parameters
client = CayleyClient("http://localhost:64210","v1")
g = GraphObject()
#Query all vertices in the graph, limit to the first 5 vertices found.
g.Vertex().GetLimit(5)
#Start with only one vertex, the literal name "Humphrey Bogart", and retrieve all of them.
query=g.Vertex("Humphrey Bogart").All();
response = client.Send(query)
#response.result contains JSON data and response.r contains raw response
print response.result
#`g` and `V` are synonyms for `graph` and `Vertex` respectively, as they are quite common.
query=g.V("Humphrey Bogart").All()
response = client.Send(query)
#"Humphrey Bogart" is a name, but not an entity. Let's find the entities with this name in our dataset.
#Follow links that are pointing In to our "Humphrey Bogart" node with the predicate "name".
query = g.V("Humphrey Bogart").In("name").All()
response = client.Send(query)
#Notice that "name" is a generic predicate in our dataset.
#Starting with a movie gives a similar effect.
query = g.V("Casablanca").In("name").All()
response = client.Send(query)
#Relatedly, we can ask the reverse; all ids with the name "Casablanca"
query = g.V().Has("name", "Casablanca").All()
response = client.Send(query)
#Let's get the list of actors in the film
query = g.V().Has("name", "Casablanca") \
.Out("/film/film/starring") \
.Out("/film/performance/actor") \
.Out("name") \
.All()
response = client.Send(query)
#But this is starting to get long. Let's use a morphism -- a pre-defined path stored in a variable -- as our linkage
film_to_actor = g.Morphism().Out("/film/film/starring").Out("/film/performance/actor")
query = g.V() \
.Has("name", "Casablanca") \
.Follow(film_to_actor) \
.Out("name") \
.All()
response = client.Send(query)
# Test data
# class Identity(Jsonable):
# def __init__(self):
# self.name = "abc name"
# self.first = "abc first"
# self.addr = Addr()
#
#
# class Addr(Jsonable):
# def __init__(self):
# self.street = "sesame street"
# self.zip = "13000"
#
#
# class Doc(Jsonable):
# def __init__(self):
# self.identity = Identity()
# self.data = "all data"
# write usage
client = CayleyClient()
b = Doc()
jsonData = json.loads(json.dumps(dict(b), sort_keys=True))
inputParams = [
{
'data': jsonData,
'subject': 'this a book',
'label': 'ituring',
'isBlankNode': None
}
]
result = client.Write(inputParams)
# read usage
client = CayleyClient()
result = client.Read()
# delete usage
client = CayleyClient()
b = Doc()
jsonData = json.loads(json.dumps(dict(b), sort_keys=True))
inputParams = [
{
'data': jsonData,
'subject': 'this a book',
'label': 'ituring',
'isBlankNode': None
}
]
result = client.Delete(inputParams)
Bugs
If you encounter a bug, performance issue, or malfunction, please add an Issue with steps on how to reproduce the problem.
TODO
- Improve Gremlin implementation (Basic steps implemented at the moment)
- Add more tests
- Add more documentation
- convert quadruple to json or json-ld
Open Source Projects in Use
- requests by @kennethreitz
License
Code and documentation are available according to the MIT License (see LICENSE).