vnf_id2vnf_name = defaultdict(lambda: "NotExistingNode",
reduce(lambda x, y: dict(x, **y),
map(lambda d: {d["vnf_id"]: d["vnf_name"]},
vnf_id2vnf_name = defaultdict(lambda: "NotExistingNode",
reduce(lambda x, y: dict(x, **y),
map(lambda d: {d["vnf_id"]: d["vnf_name"]},