class Graph(object):
"""
The primary interface to graph databases on the Rexster REST server.
Instantiates the database :class:`~bulbs.rest.Resource` object using
the specified database URL and sets up proxy objects to the database.
:keyword db_url: The URL to the specific database on Rexster.
:ivar vertices: :class:`~bulbs.element.VertexProxy` object for the Resource.
:ivar edges: :class:`~bulbs.element.EdgeProxy` object for the Resource.
:ivar indices: :class:`~bulbs.index.IndexProxy` object for the Resource.
:ivar gremlin: :class:`~bulbs.gremlin.Gremlin` object for the Resource.
Example::
>>> from bulbs.graph import Graph
>>> g = Graph()
>>> james = g.vertices.create({'name':'James'})
>>> julie = g.vertices.create({'name':'Julie'})
>>> g.edges.create(james,"knows",julie)
"""
def __init__(self,db_url=config.DATABASE_URL):
self.resource = Resource(db_url)
self.vertices = VertexProxy(self.resource)
self.edges = EdgeProxy(self.resource)
self.indices = IndexProxy(self.resource)
self.gremlin = Gremlin(self.resource)
#def __rshift__(self,b):
# return list(self)
@property
def V(self):
"""
Returns all the vertices of the graph.
Example::
>>> g = Graph()
>>> vertices = g.V
:rtype: List of :class:`~bulbs.element.Vertex` objects.
"""
vertices = self.gremlin.query("g.V",Vertex,raw=True)
return list(vertices)
@property
def E(self):
"""
Returns all the edges of the graph.
Example::
>>> g = Graph()
>>> edges = g.E
:rtype: List of :class:`~bulbs.element.Edge` objects.
"""
edges = self.gremlin.query("g.E",Edge,raw=True)
return list(edges)
def idxV(self,**kwds):
"""
Looks up a key/value pair in the vertex index and
returns a generator containing the vertices matching the key and value.
:keyword pair: The key/value pair to match on.
:keyword raw: Boolean. If True, return the raw Response object.
Defaults to False.
Example::
>>> g = Graph()
>>> vertices = g.idxV(name="James")
:rtype: Generator of :class:`~bulbs.element.Vertex` objects.
You can turn the generator into a list by doing::
>>> vertices = g.idxV(name="James")
>>> vertices = list(vertices)
"""
return self._idx("vertices",**kwds)
#def _initialize_results(self,results,raw):
# if raw is True:
# return (result for result in results)
# else:
# return (Vertex(self.resource,result) for result in results)
def idxE(self,**kwds):
"""
Looks up a key/value pair in the edge index and
returns a generator containing the edges matching the key and value.
:keyword pair: The key/value pair to match on.
:keyword raw: Boolean. If True, return the raw Response object.
Defaults to False.
Example::
>>> g = Graph()
>>> edges = g.idxE(label="knows")
:rtype: Generator of :class:`~bulbs.element.Edge` objects.
You can turn the generator into a list by doing::
>>> edges = g.idxE(label="knows")
>>> edges = list(edges)
"""
return self._idx("edges",**kwds)
def _idx(self,index_name,**kwds):
"""
Returns the Rexster Response object of the index look up.
:param index_name: The name of the index.
:param pair: The key/value pair to match on.
:keyword raw: Boolean. If True, return the raw Response object.
Defaults to False.
"""
raw = kwds.pop("raw",False)
key, value = kwds.popitem()
target = "%s/indices/%s" % (self.resource.db_name,index_name)
params = dict(key=key,value=value)
resp = self.resource.get(target,params)
if raw:
return resp
if resp.results:
class_map = dict(vertices=Vertex,edges=Edge)
element_class = class_map[index_name]
return (element_class(self.resource,result) for result in resp.results)
def load_graphml(self,url):
"""
Loads a GraphML file into the database, and returns the Rexster
response object.
:param url: The URL of the GraphML file to load.
"""
script = "g.loadGraphML('%s')" % url
resp = self.gremlin.execute(script)
return resp
def save_graphml(self):
"""
Returns a GraphML file representing the entire database.
"""
script = """
g.saveGraphML('data/graphml');
new File('data/graphml').getText();
"""
results = self.gremlin.execute(script)
return results[0]
def clear(self):
"""
Deletes all the elements in the graph.
Example::
>>> g = Graph()
>>> g.clear()
.. admonition:: WARNING
g.clear() will delete all your data!
"""
target = self.resource.db_name
resp = self.resource.delete(target,params=None)
return resp
class Graph(object):
"""
The primary interface to graph databases on the Rexster REST server.
Instantiates the database :class:`~bulbs.rest.Resource` object using
the specified database URL and sets up proxy objects to the database.
:keyword db_url: The URL to the specific database on Rexster.
:ivar vertices: :class:`~bulbs.element.VertexProxy` object for the Resource.
:ivar edges: :class:`~bulbs.element.EdgeProxy` object for the Resource.
:ivar indices: :class:`~bulbs.index.IndexProxy` object for the Resource.
:ivar gremlin: :class:`~bulbs.gremlin.Gremlin` object for the Resource.
Example::
>>> from bulbs.graph import Graph
>>> g = Graph()
>>> james = g.vertices.create({'name':'James'})
>>> julie = g.vertices.create({'name':'Julie'})
>>> g.edges.create(james,"knows",julie)
"""
def __init__(self, db_url=config.DATABASE_URL):
self.resource = Resource(db_url)
self.vertices = VertexProxy(self.resource)
self.edges = EdgeProxy(self.resource)
self.indices = IndexProxy(self.resource)
self.gremlin = Gremlin(self.resource)
#def __rshift__(self,b):
# return list(self)
@property
def V(self):
"""
Returns all the vertices of the graph.
Example::
>>> g = Graph()
>>> vertices = g.V
:rtype: List of :class:`~bulbs.element.Vertex` objects.
"""
vertices = self.gremlin.query("g.V", Vertex, raw=True)
return list(vertices)
@property
def E(self):
"""
Returns all the edges of the graph.
Example::
>>> g = Graph()
>>> edges = g.E
:rtype: List of :class:`~bulbs.element.Edge` objects.
"""
edges = self.gremlin.query("g.E", Edge, raw=True)
return list(edges)
def idxV(self, **kwds):
"""
Looks up a key/value pair in the vertex index and
returns a generator containing the vertices matching the key and value.
:keyword pair: The key/value pair to match on.
:keyword raw: Boolean. If True, return the raw Response object.
Defaults to False.
Example::
>>> g = Graph()
>>> vertices = g.idxV(name="James")
:rtype: Generator of :class:`~bulbs.element.Vertex` objects.
You can turn the generator into a list by doing::
>>> vertices = g.idxV(name="James")
>>> vertices = list(vertices)
"""
return self._idx("vertices", **kwds)
#def _initialize_results(self,results,raw):
# if raw is True:
# return (result for result in results)
# else:
# return (Vertex(self.resource,result) for result in results)
def idxE(self, **kwds):
"""
Looks up a key/value pair in the edge index and
returns a generator containing the edges matching the key and value.
:keyword pair: The key/value pair to match on.
:keyword raw: Boolean. If True, return the raw Response object.
Defaults to False.
Example::
>>> g = Graph()
>>> edges = g.idxE(label="knows")
:rtype: Generator of :class:`~bulbs.element.Edge` objects.
You can turn the generator into a list by doing::
>>> edges = g.idxE(label="knows")
>>> edges = list(edges)
"""
return self._idx("edges", **kwds)
def _idx(self, index_name, **kwds):
"""
Returns the Rexster Response object of the index look up.
:param index_name: The name of the index.
:param pair: The key/value pair to match on.
:keyword raw: Boolean. If True, return the raw Response object.
Defaults to False.
"""
raw = kwds.pop("raw", False)
key, value = kwds.popitem()
target = "%s/indices/%s" % (self.resource.db_name, index_name)
params = dict(key=key, value=value)
resp = self.resource.get(target, params)
if raw:
return resp
if resp.results:
class_map = dict(vertices=Vertex, edges=Edge)
element_class = class_map[index_name]
return (element_class(self.resource, result)
for result in resp.results)
def load_graphml(self, url):
"""
Loads a GraphML file into the database, and returns the Rexster
response object.
:param url: The URL of the GraphML file to load.
"""
script = "g.loadGraphML('%s')" % url
resp = self.gremlin.execute(script)
return resp
def save_graphml(self):
"""
Returns a GraphML file representing the entire database.
"""
script = """
g.saveGraphML('data/graphml');
new File('data/graphml').getText();
"""
results = self.gremlin.execute(script)
return results[0]
def clear(self):
"""
Deletes all the elements in the graph.
Example::
>>> g = Graph()
>>> g.clear()
.. admonition:: WARNING
g.clear() will delete all your data!
"""
target = self.resource.db_name
resp = self.resource.delete(target, params=None)
return resp
