cassandra.graph - Graph Statements, Options, and Row Factories¶

cassandra.graph.single_object_row_factory(column_names, rows)[source]¶

returns the JSON string value of graph results

cassandra.graph.graph_result_row_factory(column_names, rows)[source]¶

Returns a Result object that can load graph results and produce specific types. The Result JSON is deserialized and unpacked from the top-level ‘result’ dict.

cassandra.graph.graph_object_row_factory(column_names, rows)[source]¶

Like graph_result_row_factory(), except known element types (Vertex, Edge) are converted to their simplified objects. Some low-level metadata is shed in this conversion. Unknown result types are still returned as Result.

class cassandra.graph.GraphProtocol[source]¶

GRAPHSON_1_0 = b'graphson-1.0'¶

GraphSON1

GRAPHSON_2_0 = b'graphson-2.0'¶

GraphSON2

GRAPHSON_3_0 = b'graphson-3.0'¶

GraphSON3

class cassandra.graph.GraphOptions(**kwargs)[source]¶

Options for DSE Graph Query handler.

graph_name¶

name of the targeted graph.

graph_source¶

choose the graph traversal source, configured on the server side.

graph_language¶

the language used in the queries (default “gremlin-groovy”)

graph_read_consistency_level¶

read cassandra.ConsistencyLevel for graph queries (if distinct from session default). Setting this overrides the native Statement.consistency_level for read operations from Cassandra persistence

graph_write_consistency_level¶

write cassandra.ConsistencyLevel for graph queries (if distinct from session default). Setting this overrides the native Statement.consistency_level for write operations to Cassandra persistence.

is_default_source¶

is_analytics_source¶

True if graph_source is set to the server-defined analytics traversal source (‘a’)

is_graph_source¶

True if graph_source is set to the server-defined graph traversal source (‘g’)

set_source_default()[source]¶

Sets graph_source to the server-defined default traversal source (‘default’)

set_source_analytics()[source]¶

Sets graph_source to the server-defined analytic traversal source (‘a’)

set_source_graph()[source]¶

Sets graph_source to the server-defined graph traversal source (‘g’)

class cassandra.graph.SimpleGraphStatement(query_string, retry_policy=None, consistency_level=None, routing_key=None, serial_consistency_level=None, fetch_size=<object object>, keyspace=None, custom_payload=None, is_idempotent=False)[source]¶

Simple graph statement for Session.execute_graph(). Takes the same parameters as SimpleStatement.

query_string should be a literal CQL statement with the exception of parameter placeholders that will be filled through the parameters argument of Session.execute().

See Statement attributes for a description of the other parameters.

class cassandra.graph.Result(value)[source]¶

Represents deserialized graph results. Property and item getters are provided for convenience.

value = None¶

Deserialized value from the result

as_vertex()[source]¶

Return a Vertex parsed from this result

Raises TypeError if parsing fails (i.e. the result structure is not valid).

as_edge()[source]¶

Return a Edge parsed from this result

Raises TypeError if parsing fails (i.e. the result structure is not valid).

as_path()[source]¶

Return a Path parsed from this result

Raises TypeError if parsing fails (i.e. the result structure is not valid).

class cassandra.graph.Vertex(id, label, type, properties)[source]¶

Represents a Vertex element from a graph query.

Vertex properties are extracted into a dict of property names to list of VertexProperty (list because they are always encoded that way, and sometimes have multiple cardinality; VertexProperty because sometimes the properties themselves have property maps).

class cassandra.graph.VertexProperty(label, value, properties=None)[source]¶

Vertex properties have a top-level value and an optional dict of properties.

label = None¶

label of the property

value = None¶

Value of the property

properties = None¶

dict of properties attached to the property

class cassandra.graph.Edge(id, label, type, properties, inV, inVLabel, outV, outVLabel)[source]¶

Represents an Edge element from a graph query.

Attributes match initializer parameters.

class cassandra.graph.Path(labels, objects)[source]¶

Represents a graph path.

Labels list is taken verbatim from the results.

Objects are either Result or Vertex/Edge for recognized types

labels = None¶

List of labels in the path

objects = None¶

List of objects in the path

class cassandra.graph.GraphSON1Serializer[source]¶

Serialize python objects to graphson types.

class cassandra.graph.GraphSON1Deserializer[source]¶

Deserialize graphson1 types to python objects.

classmethod deserialize_date(value)[source]¶

classmethod deserialize_timestamp(value)[source]¶

classmethod deserialize_time(value)[source]¶

classmethod deserialize_duration(value)[source]¶

classmethod deserialize_int(value)[source]¶

classmethod deserialize_bigint(value)[source]¶

classmethod deserialize_double(value)[source]¶

classmethod deserialize_float(value)¶

classmethod deserialize_uuid(value)[source]¶

classmethod deserialize_blob(value)[source]¶

classmethod deserialize_decimal(value)[source]¶

classmethod deserialize_point(value)[source]¶

classmethod deserialize_linestring(value)[source]¶

classmethod deserialize_polygon(value)[source]¶

class cassandra.graph.GraphSON2Reader(context, extra_deserializer_map=None)[source]¶

GraphSON2 Reader that parse json and deserialize to python objects.

Parameters

extra_deserializer_map – map from GraphSON type tag to deserializer instance implementing deserialize

read(json_data)[source]¶

Read and deserialize json_data.

deserialize(obj)[source]¶

Deserialize GraphSON type-tagged dict values into objects mapped in self.deserializers