single_source_bellman_ford¶

single_source_bellman_ford(G, source, target=None, cutoff=None, weight='weight')[source]¶

Compute shortest paths and lengths in a weighted graph G.

Uses Bellman-Ford algorithm for shortest paths.

Parameters:	G (NetworkX graph) source (node label) – Starting node for path target (node label, optional) – Ending node for path cutoff (integer or float, optional) – Depth to stop the search. Only paths of length <= cutoff are returned.
Returns:	distance,path – Returns a tuple of two dictionaries keyed by node. The first dictionary stores distance from the source. The second stores the path from the source to that node.
Return type:	dictionaries

Examples

>>> G=nx.path_graph(5)
>>> length,path=nx.single_source_bellman_ford(G,0)
>>> print(length[4])
4
>>> print(length)
{0: 0, 1: 1, 2: 2, 3: 3, 4: 4}
>>> path[4]
[0, 1, 2, 3, 4]

Notes

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