def graph_to_triples(digraph, sent):
    """
    Convert a single graph to triples
    """
    return ["{}\t{}\t{}".format(" ".join(sent[u[0]: u[1]]),
                                " ".join(digraph[u][v]["label"]),
                                " ".join(sent[v[0]: v[1]]))
            for (u, v) in digraph.edges()]