Skip to main content
`Ctrl`+`K`

# read_adjlist

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

  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 constructor, optional (default=nx.Graph)

      Graph type to create. If graph instance, then cleared before populated.

    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.

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

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