Gremlin-Python 查找由边连接的所有节点

Question

I have a list of node labels as node_labels , where some of these may exist in a graph.

node_labels = ['a', 'b', 'c']

Using this I can get the node labels or associated attributes.

g.V().has_label(*node_labels).to_list()

How can I modify the query so that I get only those node(s) where an edge exists (either incoming or outgoing) between the nodes?

Answer 1

If I understand properly, said another way, you want any vertex with those labels if that vertex connects to another vertex with one those labels:

g.V().has_label(*node_labels).
  filter(both().has_label(*node_labels))

Here's a working example:

gremlin> g = TinkerFactory.createModern().traversal()
==>graphtraversalsource[tinkergraph[vertices:6 edges:6], standard]
gremlin> g.V().hasLabel('person')
==>v[1]
==>v[2]
==>v[4]
==>v[6]
gremlin> g.V().hasLabel('person').where(both().hasLabel('person'))
==>v[1]
==>v[2]
==>v[4]