def highest_centrality(centrality_function):
     """Returns a tuple (node,value) with the node
    with largest value from Networkx centrality dictionary."""
     # Create ordered tuple of centrality data
     cent_items=[(b,a) for (a,b) in centrality_function.iteritems()]
     # Sort in descending order
     cent_items.sort()
     cent_items.reverse()
     return tuple(reversed(cent_items[0]))