read_gml¶

read_gml(path, label='label', destringizer=None)[source]¶

Read graph in GML format from path.

Parameters

pathfilename or filehandle: The filename or filehandle to read from.
labelstring, optional: If not None, the parsed nodes will be renamed according to node attributes indicated by label. Default value: ‘label’.
destringizercallable, optional: A destringizer that recovers values stored as strings in GML. If it cannot convert a string to a value, a ValueError is raised. Default value : None.

Returns

GNetworkX graph: The parsed graph.

Raises

NetworkXError: If the input cannot be parsed.

See also

write_gml, parse_gml
literal_destringizer

Notes

GML files are stored using a 7-bit ASCII encoding with any extended ASCII characters (iso8859-1) appearing as HTML character entities. Without specifying a stringizer/destringizer, the code is capable of writing int/float/str/dict/list data as required by the GML specification. For writing other data types, and for reading data other than str you need to explicitly supply a stringizer/destringizer.

For additional documentation on the GML file format, please see the GML url.

See the module docstring networkx.readwrite.gml for more details.

Examples

>>> G = nx.path_graph(4)
>>> nx.write_gml(G, "test.gml")

GML values are interpreted as strings by default:

>>> H = nx.read_gml("test.gml")
>>> H.nodes
NodeView(('0', '1', '2', '3'))

When a destringizer is provided, GML values are converted to the provided type. For example, integer nodes can be recovered as shown below:

>>> J = nx.read_gml("test.gml", destringizer=int)
>>> J.nodes
NodeView((0, 1, 2, 3))