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



Return the disjoint union of all graphs.

This operation forces distinct integer node labels starting with 0 for the first graph in the list and numbering consecutively.

Parameters:graphs (list) – List of NetworkX graphs
Return type:A graph with the same type as the first graph in list


It is recommended that the graphs be either all directed or all undirected.

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.