def del_big_nodes(self, grater_than=215):
        """Delete big nodes with many connections from the graph."""
        G = self._graph
        it = G.nodes_iter()
        node_paths = []
        node_names = []
        del_nodes = []
        summe = 1
        count = 1
        for node in it:
            l = len(G[node])
            if l > grater_than:
                del_nodes.append(node)
                continue
            summe += l
            node_names.append(node)
            node_paths.append(l)
            count += 1
        for node in del_nodes:
            G.remove_node(node)
            if node > 1000000000:
                self.valid_user.pop(node)

        print("Nodes deleted: {}".format(len(del_nodes)))
Delete big nodes with many connections from the graph.