如何在python gremlin中检索顶点的属性值

Question

这可能很容易，但我真的在努力解决这个问题。我使用gremlin python lib和aws neptune db。 我知道顶点id，我只想得到顶点的一个属性的值（python中的字符串类型），并更新它。你知道吗

我试过这样做：

print(g.V(event['securityEventManagerId']).values('sourceData'))
print(g.V(event['securityEventManagerId']).property('sourceData'))
print(g.V(event['securityEventManagerId']).property('sourceData').valueMap())
.....

但是我只打印了一些python gremlin对象，比如GraphTraversal，无法将值检索为string

有人能帮我吗？你知道吗

Answer 1

必须使用终端步骤，否则查询将无法执行。你知道吗

来自tinkerpopdocumentation：

Typically, when a step is concatenated to a traversal a traversal is returned. In this way, a traversal is built up in a fluent, monadic fashion. However, some steps do not return a traversal, but instead, execute the traversal and return a result. These steps are known as terminal steps (terminal) and they are explained via the examples below.

在您的情况下，您应该：

g.V(event['securityEventManagerId']).values('sourceData').next()