is_weakly_connected

is_weakly_connected(G)

Test directed graph for weak connectivity.

A directed graph is weakly connected if and only if the graph is connected when the direction of the edge between nodes is ignored.

Note that if a graph is strongly connected (i.e. the graph is connected even when we account for directionality), it is by definition weakly connected as well.

Parameters:

GNetworkX Graph

A directed graph.

Returns:

connectedbool

True if the graph is weakly connected, False otherwise.

Raises:

NetworkXNotImplemented

If G is undirected.

See also

is_strongly_connected

is_semiconnected

is_connected

is_biconnected

weakly_connected_components

Notes

For directed graphs only.

Examples

>>> G = nx.DiGraph([(0, 1), (2, 1)])
>>> G.add_node(3)
>>> nx.is_weakly_connected(G)  # node 3 is not connected to the graph
False
>>> G.add_edge(2, 3)
>>> nx.is_weakly_connected(G)
True