write_graph6(G, path, nodes=None, header=True)[source]

Write a simple undirected graph to a path in graph6 format.

Parameters
• G (Graph (undirected))

• path (str) – The path naming the file to which to write the graph.

• nodes (list or iterable) – Nodes are labeled 0…n-1 in the order provided. If None the ordering given by G.nodes() is used.

Raises
• NetworkXNotImplemented – If the graph is directed or is a multigraph.

• ValueError – If the graph has at least 2 ** 36 nodes; the graph6 format is only defined for graphs of order less than 2 ** 36.

Examples

You can write a graph6 file by giving the path to a file:

>>> import tempfile
>>> with tempfile.NamedTemporaryFile() as f:
...     nx.write_graph6(nx.path_graph(2), f.name)
...     _ = f.seek(0)
b'>>graph6<<A_\n'


Notes

The function writes a newline character after writing the encoding of the graph.

The format does not support edge or node labels, parallel edges or self loops. If self loops are present they are silently ignored.

References

1

Graph6 specification <http://users.cecs.anu.edu.au/~bdm/data/formats.html>