networkx.algorithms.shortest_paths.weighted.all_pairs_bellman_ford_path_length

all_pairs_bellman_ford_path_length(G, weight='weight')[source]

Compute shortest path lengths between all nodes in a weighted graph.

Parameters
  • G (NetworkX graph)

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

Returns

distance – (source, dictionary) iterator with dictionary keyed by target and shortest path length as the key value.

Return type

iterator

Examples

>>> G = nx.path_graph(5)
>>> length = dict(nx.all_pairs_bellman_ford_path_length(G))
>>> for node in [0, 1, 2, 3, 4]:
...     print('1 - {}: {}'.format(node, length[1][node]))
1 - 0: 1
1 - 1: 0
1 - 2: 1
1 - 3: 2
1 - 4: 3
>>> length[3][2]
1
>>> length[2][2]
0

Notes

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

The dictionary returned only has keys for reachable node pairs.