DiGraph.number_of_edges

DiGraph.number_of_edges(u=None, v=None)

Returns the number of edges between two nodes.

Parameters:

u, vnodes, optional (default=all edges)

If u and v are specified, return the number of edges between u and v. Otherwise return the total number of all edges.

Returns:

nedgesint

The number of edges in the graph. If nodes u and v are specified return the number of edges between those nodes. If the graph is directed, this only returns the number of edges from u to v.

See also

size

Examples

For undirected graphs, this method counts the total number of edges in the graph:

>>> G = nx.path_graph(4)
>>> G.number_of_edges()
3

If you specify two nodes, this counts the total number of edges joining the two nodes:

>>> G.number_of_edges(0, 1)
1

For directed graphs, this method can count the total number of directed edges from u to v:

>>> G = nx.DiGraph()
>>> G.add_edge(0, 1)
>>> G.add_edge(1, 0)
>>> G.number_of_edges(0, 1)
1