kosaraju_strongly_connected_components#

kosaraju_strongly_connected_components(G, source=None)[source]#

Generate nodes in strongly connected components of graph.

Parameters:

GNetworkX Graph: A directed graph.
sourcenode, optional (default=None): Specify a node from which to start the depth-first search. If not provided, the algorithm will start from an arbitrary node.

Yields:

set: A set of all nodes in a strongly connected component of G.

Raises:

NetworkXNotImplemented: If G is undirected.
NetworkXError: If source is not a node in G.

See also

strongly_connected_components

Notes

Uses Kosaraju’s algorithm.

Examples

Generate a list of strongly connected components of a graph:

>>> G = nx.cycle_graph(4, create_using=nx.DiGraph())
>>> nx.add_cycle(G, [10, 11, 12])
>>> sorted(nx.kosaraju_strongly_connected_components(G), key=len, reverse=True)
[{0, 1, 2, 3}, {10, 11, 12}]

If you only want the largest component, it’s more efficient to use max() instead of sorted().

>>> max(nx.kosaraju_strongly_connected_components(G), key=len)
{0, 1, 2, 3}