Note

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

networkx.algorithms.components.is_semiconnected

is_semiconnected(G, topo_order=None)[source]

Returns True if the graph is semiconnected, False otherwise.

A graph is semiconnected if, and only if, for any pair of nodes, either one is reachable from the other, or they are mutually reachable.

Parameters
GNetworkX graph

A directed graph.

topo_order: list or tuple, optional

A topological order for G (if None, the function will compute one)

Returns
semiconnectedbool

True if the graph is semiconnected, False otherwise.

Raises
NetworkXNotImplemented

If the input graph is undirected.

NetworkXPointlessConcept

If the graph is empty.

Examples

>>> G = nx.path_graph(4, create_using=nx.DiGraph())
>>> print(nx.is_semiconnected(G))
True
>>> G = nx.DiGraph([(1, 2), (3, 2)])
>>> print(nx.is_semiconnected(G))
False