all_shortest_paths#
- all_shortest_paths(G, source, target, weight=None, method='dijkstra')[source]#
Compute all shortest simple paths in the graph.
- Parameters:
- GNetworkX graph
- sourcenode
Starting node for path.
- targetnode
Ending node for path.
- weightNone, string or function, optional (default = None)
If None, every edge has weight/distance/cost 1. If a string, use this edge attribute as the edge weight. Any edge attribute not present defaults to 1. 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.
- methodstring, optional (default = ‘dijkstra’)
The algorithm to use to compute the path lengths. Supported options: ‘dijkstra’, ‘bellman-ford’. Other inputs produce a ValueError. If
weight
is None, unweighted graph methods are used, and this suggestion is ignored.
- Returns:
- pathsgenerator of lists
A generator of all paths between source and target.
- Raises:
- ValueError
If
method
is not among the supported options.- NetworkXNoPath
If
target
cannot be reached fromsource
.
See also
shortest_path
single_source_shortest_path
all_pairs_shortest_path
Notes
There may be many shortest paths between the source and target. If G contains zero-weight cycles, this function will not produce all shortest paths because doing so would produce infinitely many paths of unbounded length – instead, we only produce the shortest simple paths.
Examples
>>> G = nx.Graph() >>> nx.add_path(G, [0, 1, 2]) >>> nx.add_path(G, [0, 10, 2]) >>> print([p for p in nx.all_shortest_paths(G, source=0, target=2)]) [[0, 1, 2], [0, 10, 2]]