python - 如何在 python gremlin 中检索顶点的属性值

Question

这可能很容易，但我真的很难解决这个问题。我使用 gremlin python 库和 aws 海王星数据库。我知道顶点id，我只想获取顶点属性之一的值(python中的String类型)，并更新它。

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())
.....

但我只是打印一些 python gremlin 对象，例如 GraphTraversal，无法将值检索为 string

谁能帮帮我？

Answer 1

您必须使用终端步骤，否则您的查询将不会执行。

来自 tinkerpop documentation :

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.

在你的情况下，你应该这样做:

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