single_source_bellman_ford_path_length#
- single_source_bellman_ford_path_length(G, source, weight='weight')[source]#
Compute the shortest path length between source and all other reachable nodes for a weighted graph.
- Parameters:
- GNetworkX graph
- sourcenode label
Starting node for path
- weightstring or function (default=”weight”)
If this is a string, then edge weights will be accessed via the edge attribute with this key (that is, the weight of the edge joining
u
tov
will beG.edges[u, v][weight]
). If no such edge attribute exists, the weight of the edge is assumed to be one.If this is a function, the weight of an edge is the value returned by the function. The function must accept exactly three positional arguments: the two endpoints of an edge and the dictionary of edge attributes for that edge. The function must return a number.
- Returns:
- lengthiterator
(target, shortest path length) iterator
- Raises:
- NodeNotFound
If
source
is not inG
.
Notes
Edge weight attributes must be numerical. Distances are calculated as sums of weighted edges traversed.
Examples
>>> G = nx.path_graph(5) >>> length = dict(nx.single_source_bellman_ford_path_length(G, 0)) >>> length[4] 4 >>> for node in [0, 1, 2, 3, 4]: ... print(f"{node}: {length[node]}") 0: 0 1: 1 2: 2 3: 3 4: 4