Yaweni

#Edge contraction as per http://en.wikipedia.org/wiki/Edge_contraction

def contract_edges(G, nodes, new_node, ):

    G2 = nx.MultiGraph()
    G2.add_nodes_from(G.nodes(data=True))
    G2.add_edges_from(G.edges(data=True))
    # Add the node with its attributes
    G2.add_node(new_node)
    # Create the set of the edges that are to be contracted