node_link_data

node_link_data(G, *, source='source', target='target', name='id', key='key', edges=None, nodes='nodes', link=None)

Returns data in node-link format that is suitable for JSON serialization and use in JavaScript documents.

Parameters:

GNetworkX graph

sourcestring

A string that provides the ‘source’ attribute name for storing NetworkX-internal graph data.

targetstring

A string that provides the ‘target’ attribute name for storing NetworkX-internal graph data.

namestring

A string that provides the ‘name’ attribute name for storing NetworkX-internal graph data.

keystring

A string that provides the ‘key’ attribute name for storing NetworkX-internal graph data.

edgesstring

A string that provides the ‘edges’ attribute name for storing NetworkX-internal graph data.

nodesstring

A string that provides the ‘nodes’ attribute name for storing NetworkX-internal graph data.

linkstring

Deprecated since version 3.4: The link argument is deprecated and will be removed in version 3.6. Use the edges keyword instead.

A string that provides the ‘edges’ attribute name for storing NetworkX-internal graph data.

Returns:

datadict

A dictionary with node-link formatted data.

Raises:

NetworkXError

If the values of ‘source’, ‘target’ and ‘key’ are not unique.

See also

node_link_graph, adjacency_data, tree_data

Notes

Graph, node, and link attributes are stored in this format. Note that attribute keys will be converted to strings in order to comply with JSON.

Attribute ‘key’ is only used for multigraphs.

To use node_link_data in conjunction with node_link_graph, the keyword names for the attributes must match.

Examples

>>> from pprint import pprint
>>> G = nx.Graph([("A", "B")])
>>> data1 = nx.node_link_data(G, edges="edges")
>>> pprint(data1)
{'directed': False,
 'edges': [{'source': 'A', 'target': 'B'}],
 'graph': {},
 'multigraph': False,
 'nodes': [{'id': 'A'}, {'id': 'B'}]}

To serialize with JSON

>>> import json
>>> s1 = json.dumps(data1)
>>> s1
'{"directed": false, "multigraph": false, "graph": {}, "nodes": [{"id": "A"}, {"id": "B"}], "edges": [{"source": "A", "target": "B"}]}'

A graph can also be serialized by passing node_link_data as an encoder function.

>>> s1 = json.dumps(G, default=nx.node_link_data)
>>> s1
'{"directed": false, "multigraph": false, "graph": {}, "nodes": [{"id": "A"}, {"id": "B"}], "links": [{"source": "A", "target": "B"}]}'

The attribute names for storing NetworkX-internal graph data can be specified as keyword options.

>>> H = nx.gn_graph(2)
>>> data2 = nx.node_link_data(
...     H, edges="links", source="from", target="to", nodes="vertices"
... )
>>> pprint(data2)
{'directed': True,
 'graph': {},
 'links': [{'from': 1, 'to': 0}],
 'multigraph': False,
 'vertices': [{'id': 0}, {'id': 1}]}