Return the edges of an Eulerian circuit in G.
An Eulerian circuit is a path that crosses every edge in G exactly once and finishes at the starting node.
- G (NetworkX Graph or DiGraph) – A directed or undirected graph
- source (node, optional) – Starting node for circuit.
edges – A generator that produces edges in the Eulerian circuit.
NetworkXError– If the graph is not Eulerian.
 J. Edmonds, E. L. Johnson. Matching, Euler tours and the Chinese postman. Mathematical programming, Volume 5, Issue 1 (1973), 111-114.  http://en.wikipedia.org/wiki/Eulerian_path
>>> G=nx.complete_graph(3) >>> list(nx.eulerian_circuit(G)) [(0, 2), (2, 1), (1, 0)] >>> list(nx.eulerian_circuit(G,source=1)) [(1, 2), (2, 0), (0, 1)] >>> [u for u,v in nx.eulerian_circuit(G)] # nodes in circuit [0, 2, 1]