read_multiline_adjlist#

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

Read graph in multi-line adjacency list format from path.

Parameters:

pathstring or file: Filename or file handle to read. Filenames ending in .gz or .bz2 will be decompressed.
create_usingNetworkX graph constructor, optional (default=nx.Graph): Graph type to create. If graph instance, then cleared before populated.
nodetypePython type, optional: Convert nodes to this type.
edgetypePython type, optional: Convert edge data to this type.
commentsstring, optional: Marker for comment lines
delimiterstring, optional: Separator for node labels. The default is whitespace.

Returns:

GNetworkX graph

See also

write_multiline_adjlist

Notes

This format does not store graph, node, or edge data.

Examples

>>> from pathlib import Path
>>> import tempfile
>>> tmp_path = Path(tempfile.gettempdir())

>>> G = nx.path_graph(4)
>>> fpath = tmp_path / "test.multi_adjlistP4"
>>> nx.write_multiline_adjlist(G, fpath)
>>> H = nx.read_multiline_adjlist(fpath)

Data read from the file are interpreted as strings by default, regardless of the node type of the original graph.

>>> G.edges
EdgeView([(0, 1), (1, 2), (2, 3)])
>>> H.edges
EdgeView([('0', '1'), ('1', '2'), ('2', '3')])

The node data can be converted to a specific type with the nodetype parameter.

>>> H = nx.read_multiline_adjlist(fpath, nodetype=int)
>>> H.edges
EdgeView([(0, 1), (1, 2), (2, 3)])
>>> nx.utils.edges_equal(G.edges, H.edges)
True

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 indicates the type of NetworkX graph created. The default is nx.Graph, an undirected graph. To read the data as a directed graph use:

>>> H = nx.read_multiline_adjlist(fpath, create_using=nx.DiGraph)
>>> H.is_directed()
True

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

>>> with open(fpath, "rb") as fh:
...     H = nx.read_multiline_adjlist(fh, nodetype=int)
>>> H.edges
EdgeView([(0, 1), (1, 2), (2, 3)])