Context¶
Context object¶
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class
graphscope.framework.context.BaseContext(session_id, context_key, graph)[source]¶ Base class of concrete contexts. Hold a handle of app querying context.
After evaluating an app, the context (vertex data, partial results, etc.) are preserved, and can be referenced through a handle.
We can further use the handle to retrieve data:
as a numpy.ndarray( to_numpy() ),
as a pandas.DataFrame( to_dataframe() ),
as a vineyard tensor ( to_vineyard_tensor() ),
or as a vineyard dataframe ( to_vineyard_dataframe() ).
Examples:
>>> g = get_test_property_graph() >>> sg = g.project_to_simple('person', 'knows', 'id', 'weight') >>> ret = sssp(sg, 20) >>> out = ret.to_numpy('r') >>> out.shape (20345,) >>> out = ret.to_dataframe({'id': 'v.id', 'result': 'r'}) >>> out.shape (20345, 2) >>> out = ret.to_vineyard_tensor() # return an object id >>> out = ret.to_vineyard_dataframe() # return an object id
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output(fd, selector, vertex_range=None)[source]¶ Dump results to fd. Support dumps data to local (respect to pod) files, hdfs or oss. It first write results to a vineyard dataframe, and let vineyard do the data dumping job. fd must meet specific formats, with auth information if needed. As follows:
- local
file:///tmp/result_path
- oss
oss://id:key@endpoint/bucket/object
- hdfs
hdfs://endpoint/result_path
- Parameters
fd (str) – Output location.
selector (dict) – Similar to to_dataframe.
vertex_range (dict, optional) – Similar to to_dataframe. Defaults to None.
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to_dataframe(selector, vertex_range=None)[source]¶ Return results as a pandas DataFrame
- Parameters
selector – dict The key is column name in dataframe, and the value describes how to select values of context. See more details in derived context class.
vertex_range – dict, optional, default to None. Works as slicing. The expression {‘begin’: m, ‘end’: n} select a portion of vertices from m to, but not including n. Type of m, n must be identical with vertices’ oid type. Only the sub-ranges of vertices data will be retrieved. Note the comparision is not based on numeric order, but on alphabetic order.
- Returns
pandas.DataFrame
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to_numpy(selector, vertex_range=None, axis=0)[source]¶ Return context data as numpy array
Args: selector (str): Describes how to select values of context.
See more details in derived context class.
- vertex_range (dict): optional, default to None.
Works as slicing. The expression {‘begin’: m, ‘end’: n} select a portion of vertices from m to, but not including n. Type of m, n must be identical with vertices’ oid type. Omitting the first index starts the slice at the beginning of the vertices, and omitting the second index extends the slice to the end of the vertices. Note the comparision is not based on numeric order, but on alphabetic order.
axis (int): optional, default to 0.
- Returns
numpy.ndarray.
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to_vineyard_dataframe(selector=None, vertex_range=None)[source]¶ Return results as a vineyard dataframe. Only object id is returned.
- Parameters
selector – dict Key is used as column name of the dataframe, and the value describes how to select values of context. See more details in derived context class.
vertex_range – dict, optional, default to None Works as slicing. The expression {‘begin’: m, ‘end’: n} select a portion of vertices from m to, but not including n. Type of m, n must be identical with vertices’ oid type. Only the sub-ranges of vertices data will be retrieved.
- Returns
object id of vineyard tensor
- Return type
str
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class
graphscope.framework.context.TensorContext(session_id, context_key, graph)[source]¶ Tensor context holds a tensor. Only axis is meaningful when considering a TensorContext.
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class
graphscope.framework.context.VertexDataContext(session_id, context_key, graph)[source]¶ The most simple kind of context. A vertex has a single value as results.
- The syntax of selector on vertex is:
v.id: Get the Id of vertices
v.data: Get the data of vertices (If there is any, means origin data on the graph, not results)
- The syntax of selector of edge is:
e.src: Get the source Id of edges
e.dst: Get the destination Id of edges
e.data: Get the edge data on the edges (If there is any, means origin data on the graph)
- The syntax of selector of results is:
r: Get quering results of algorithms. e.g. Rankings of vertices after doing PageRank.
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class
graphscope.framework.context.LabeledVertexDataContext(session_id, context_key, graph)[source]¶ The labeld kind of context. This context has several vertex labels and edge labels, and each label has several properties. Selection are performed on labels first, then on properties.
We use : to filter labels, and . to select properties. And the results has no property, only have labels.
- The syntax of selector of vertex is:
v:label_name.id: Get Id that belongs to a specific vertex label.
v:label_name.property_name: Get data that on a specific property of a specific vertex label.
- The syntax of selector of edge is:
e:label_name.src: Get source Id of a specific edge label.
e:label_name.dst: Get destination Id of a specific edge label.
e:label_name.property_name: Get data on a specific property of a specific edge label.
- The syntax of selector of results is:
r:label_name: Get results data of a vertex label.
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class
graphscope.framework.context.VertexPropertyContext(session_id, context_key, graph)[source]¶ The simple kind of context with property. A vertex can have multiple values (a.k.a. properties) as results.
- The syntax of selector on vertex is:
v.id: Get the Id of vertices
v.data: Get the data of vertices (If there is any, means origin data on the graph, not results)
- The syntax of selector of edge is:
e.src: Get the source Id of edges
e.dst: Get the destination Id of edges
e.data: Get the edge data on the edges (If there is any, means origin data on the graph)
- The syntax of selector of results is:
r.column_name: Get the property named column_name in results. e.g. r.hub in
graphscope.hits().