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


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

Read a graph as list of edges with numeric weights.

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

  • 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.

  • create_using (NetworkX graph constructor, optional (default=nx.Graph)) – Graph type to create. If graph instance, then cleared before populated.

  • nodetype (int, float, str, Python type, optional) – Convert node data from strings to specified type

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


G – A networkx Graph or other type specified with create_using

Return type



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

Example edgelist file format.

With numeric edge data:

# read with
# >>> G=nx.read_weighted_edgelist(fh)
# source target data
a b 1
a c 3.14159
d e 42