This documents the development version of NetworkX. Documentation for the current release can be found here.


write_edgelist(G, path, comments='#', delimiter=' ', data=True, encoding='utf-8')[source]

Write graph as a list of edges.

  • G (graph) – A NetworkX graph

  • path (file or string) – File or filename to write. If a file is provided, it must be opened in ‘wb’ mode. Filenames ending in .gz or .bz2 will be compressed.

  • comments (string, optional) – The character used to indicate the start of a comment

  • delimiter (string, optional) – The string used to separate values. The default is whitespace.

  • data (bool or list, optional) – If False write no edge data. If True write a string representation of the edge data dictionary.. If a list (or other iterable) is provided, write the keys specified in the list.

  • encoding (string, optional) – Specify which encoding to use when writing file.


>>> G = nx.path_graph(4)
>>> nx.write_edgelist(G, "test.edgelist")
>>> G = nx.path_graph(4)
>>> fh = open("test.edgelist", "wb")
>>> nx.write_edgelist(G, fh)
>>> nx.write_edgelist(G, "test.edgelist.gz")
>>> nx.write_edgelist(G, "test.edgelist.gz", data=False)
>>> G = nx.Graph()
>>> G.add_edge(1, 2, weight=7, color="red")
>>> nx.write_edgelist(G, "test.edgelist", data=False)
>>> nx.write_edgelist(G, "test.edgelist", data=["color"])
>>> nx.write_edgelist(G, "test.edgelist", data=["color", "weight"])