geoapi / pyley

Python client for an open-source graph database Cayley

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 pyley

##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)

  #Add data programatically to the JSON result list. Can be any JSON type.
  query = g.Emit({'name': "John Doe", 'age': 41, 'isActor': true})
  response = client.Send(query)

##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

##Open Source Projects in Use

• requests by @kennethreitz

##License

Code and documentation are available according to the MIT License (see LICENSE).