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This documents an unmaintained version of NetworkX. Please upgrade to a maintained version and see the current NetworkX documentation.

networkx.readwrite.gml.write_gml

write_gml(G, path, stringizer=None)[source]

Write a graph G in GML format to the file or file handle path.

Parameters:
  • G (NetworkX graph) – The graph to be converted to GML.
  • path (filename or filehandle) – The filename or filehandle to write. Files whose names end with .gz or .bz2 will be compressed.
  • stringizer (callable, optional) – A stringizer which converts non-int/non-float/non-dict values into strings. If it cannot convert a value into a string, it should raise a ValueError to indicate that. Default value: None.
Raises:

NetworkXError – If stringizer cannot convert a value into a string, or the value to convert is not a string while stringizer is None.

See also

read_gml(), generate_gml(), literal_stringizer()

Notes

Graph attributes named ‘directed’, ‘multigraph’, ‘node’ or ‘edge’, node attributes named ‘id’ or ‘label’, edge attributes named ‘source’ or ‘target’ (or ‘key’ if G is a multigraph) are ignored because these attribute names are used to encode the graph structure.

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 handling int/float/str/dict/list data as required by the GML specification. For other data types, you need to explicitly supply a stringizer/destringizer.

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

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

Examples

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

Filenames ending in .gz or .bz2 will be compressed.

>>> nx.write_gml(G, "test.gml.gz")