This documents an unmaintained version of NetworkX. Please upgrade to a maintained version and see the current NetworkX documentation.


union_all(graphs, rename=(None, ))[source]

Returns the union of all graphs.

The graphs must be disjoint, otherwise an exception is raised.

  • graphs (list of graphs) – List of NetworkX graphs
  • rename (bool , default=(None, None)) – Node names of G and H can be changed by specifying the tuple rename=(‘G-‘,’H-‘) (for example). Node “u” in G is then renamed “G-u” and “v” in H is renamed “H-v”.


Return type:

a graph with the same type as the first graph in list


ValueError – If graphs is an empty list.


To force a disjoint union with node relabeling, use disjoint_union_all(G,H) or convert_node_labels_to integers().

Graph, edge, and node attributes are propagated to the union graph. If a graph attribute is present in multiple graphs, then the value from the last graph in the list with that attribute is used.

See also

union(), disjoint_union_all()