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

Write a simple undirected graph to path in graph6 format.

Parameters :

G : Graph (undirected)

path : file or string

File or filename to write.

nodes: list or iterable

Nodes are labeled 0...n-1 in the order provided. If None the ordering given by G.nodes() is used.

header: bool

If True add ‘>>graph6<<’ string to head of data

Raises :


If the graph is directed or has parallel edges


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


Graph6 specification: http://cs.anu.edu.au/~bdm/data/formats.txt for details.


>>> G = nx.Graph([(0, 1)])
>>> nx.write_graph6(G, 'test.g6')