Note

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

# networkx.algorithms.shortest_paths.weighted.single_source_dijkstra_path¶

single_source_dijkstra_path(G, source, cutoff=None, weight='weight')[source]

Find shortest weighted paths in G from a source node.

Compute shortest path between source and all other reachable nodes for a weighted graph.

Parameters
• G (NetworkX graph)

• source (node) – Starting node for path.

• cutoff (integer or float, optional) – Depth to stop the search. Only return paths with length <= cutoff.

• weight (string or function) – 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 to v will be G.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

paths – Dictionary of shortest path lengths keyed by target.

Return type

dictionary

Raises

NodeNotFound – If source is not in G.

Examples

>>> G = nx.path_graph(5)
>>> path = nx.single_source_dijkstra_path(G, 0)
>>> path
[0, 1, 2, 3, 4]


Notes

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

The weight function can be used to hide edges by returning None. So weight = lambda u, v, d: 1 if d['color']=="red" else None will find the shortest red path.