disjoint_union#
- disjoint_union(G, H)[source]#
Combine graphs G and H. The nodes are assumed to be unique (disjoint).
This algorithm automatically relabels nodes to avoid name collisions.
- 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.
Renumbering forces G and H to be disjoint, so no exception is ever raised for a name collision. To preserve the check for common nodes, use union().
Edge and node attributes are propagated from G and H to the union graph. Graph attributes are also propagated, but if they are present in both G and H, then the value from H is used.
To combine graphs that have common nodes, consider compose(G, H) or the method, Graph.update().
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)]) ----
Additional backends implement this function
graphblas : OpenMP-enabled sparse linear algebra backend.