disjoint_union¶

disjoint_union(G, H)[source]¶

Return the disjoint union of graphs G and H.

This algorithm forces distinct integer node labels.

Parameters

G,Hgraph: A NetworkX graph

Returns

UA union graph with the same type as G.

Notes

A new graph is created, of the same class as G. It is recommended that G and H be either both directed or both undirected.

The nodes of G are relabeled 0 to len(G)-1, and the nodes of H are relabeled len(G) to len(G)+len(H)-1.

Graph, edge, and node attributes are propagated from G and H to the union graph. If a graph attribute is present in both G and H the value from H is used.

Examples

>>> G = nx.Graph([(0, 1), (0, 2), (1, 2)])
>>> H = nx.Graph([(0, 3), (1, 2), (2, 3)])
>>> G.nodes[0]["key1"] = 5
>>> H.nodes[0]["key2"] = 10
>>> U = nx.disjoint_union(G, H)
>>> U.nodes(data=True)
NodeDataView({0: {'key1': 5}, 1: {}, 2: {}, 3: {'key2': 10}, 4: {}, 5: {}, 6: {}})
>>> U.edges
EdgeView([(0, 1), (0, 2), (1, 2), (3, 4), (4, 6), (5, 6)])