#

Note

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

#

networkx.algorithms.shortest_paths.weighted.bellman_ford_path_length

bellman_ford_path_length(G, source, target, weight='weight')

Returns the shortest path length from source to target in a weighted graph.

Parameters

• G (NetworkX graph)

• source (node label) – starting node for path

• target (node label) – ending node for path

• weight (string, optional (default=’weight’)) – Edge data key corresponding to the edge weight

Returns

length – Shortest path length.

Return type

number

Raises

• NodeNotFound – If source is not in G.

• NetworkXNoPath – If no path exists between source and target.

Examples

>>> G = nx.path_graph(5)
>>> print(nx.bellman_ford_path_length(G, 0, 4))
4

Notes

Edge weight attributes must be numerical. Distances are calculated as sums of weighted edges traversed.

See also

dijkstra_path_length(), bellman_ford_path()