read_adjlist¶

read_adjlist(path, comments='#', delimiter=None, create_using=None, nodetype=None, encoding='utf-8')[source]¶

Read graph in adjacency list format from path.

Parameters:

path : string or file Filename or file handle to read. Filenames ending in .gz or .bz2 will be uncompressed. create_using: NetworkX graph container Use given NetworkX graph for holding nodes or edges. nodetype : Python type, optional Convert nodes to this type. comments : string, optional Marker for comment lines delimiter : string, optional Separator for node labels. The default is whitespace. create_using: NetworkX graph container Use given NetworkX graph for holding nodes or edges.

Returns:

G: NetworkX graph The graph corresponding to the lines in adjacency list format.

See also

write_adjlist

Notes

This format does not store graph or node data.

Examples

>>> G=nx.path_graph(4)
>>> nx.write_adjlist(G, "test.adjlist")
>>> G=nx.read_adjlist("test.adjlist")

The path can be a filehandle or a string with the name of the file. If a filehandle is provided, it has to be opened in ‘rb’ mode.

>>> fh=open("test.adjlist", 'rb')
>>> G=nx.read_adjlist(fh)

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

>>> nx.write_adjlist(G,"test.adjlist.gz")
>>> G=nx.read_adjlist("test.adjlist.gz")

The optional nodetype is a function to convert node strings to nodetype.

For example

>>> G=nx.read_adjlist("test.adjlist", nodetype=int)

will attempt to convert all nodes to integer type.

Since nodes must be hashable, the function nodetype must return hashable types (e.g. int, float, str, frozenset - or tuples of those, etc.)

The optional create_using parameter is a NetworkX graph container. The default is Graph(), an undirected graph. To read the data as a directed graph use

>>> G=nx.read_adjlist("test.adjlist", create_using=nx.DiGraph())