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')[source]

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

Parameters
GNetworkX graph
sourcenode label

starting node for path

targetnode label

ending node for path

weight: string, optional (default=’weight’)

Edge data key corresponding to the edge weight

Returns
lengthnumber

Shortest path length.

Raises
NodeNotFound

If source is not in G.

NetworkXNoPath

If no path exists between source and target.

Notes

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

Examples

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