MultiGraph.number_of_edges#

MultiGraph.number_of_edges(u=None, v=None)[source]#

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 multigraphs, this method counts the total number of edges in the graph:

>>> G = nx.MultiGraph()
>>> G.add_edges_from([(0, 1), (0, 1), (1, 2)])
[0, 1, 0]
>>> 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)
2

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

>>> G = nx.MultiDiGraph()
>>> G.add_edges_from([(0, 1), (0, 1), (1, 0)])
[0, 1, 0]
>>> G.number_of_edges(0, 1)
2
>>> G.number_of_edges(1, 0)
1
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