aanastasiou

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

def contract_edges(G,nodes, new_node, attr_dict=None, **attr):
    '''Contracts the edges of the nodes in the set "nodes" '''
    #Add the node with its attributes
    G.add_node(new_node, attr_dict, **attr)
    #Create the set of the edges that are to be contracted
    cntr_edge_set = G.edges(nodes, data = True)
    #Add edges from new_node to all target nodes in the set of edges that are to be contracted
    #Possibly also checking that edge attributes are preserved and not overwritten,