我正在尝试使用 python 在 Neo4j 中顺序插入顶点和边。当我添加边时,现有节点不会被识别。无论我使用 py2neo 还是灯泡,我都会收到类似的错误消息。
请注意我正在使用: linux64 python 2.7 灯泡0.3 py2neo1.5 neo4j-community1.8.2
带灯泡:
>>> from bulbs.neo4jserver import Graph
>>> g = Graph()
>>> g.vertices.create(name="James")
>>> g.vertices.create(name="Julie")
>>> g.edges.create(james, "knows", julie)
---------------------------------------------------------------------------
NameError Traceback (most recent call last)
<ipython-input-46-9ba24256218d> in <module>()
----> 1 g.edges.create(james, "knows", julie)
NameError: name 'james' is not defined
使用 py2neo
from py2neo import neo4j
graph=neo4j.GraphDatabaseService()
node=graph.create({"name":'James'},{'name':'Julie'})
rel=graph.create((james,"knows",julie))
---------------------------------------------------------------------------
NameError Traceback (most recent call last)
<ipython-input-8-591f826cfd05> in <module>()
2 graph=neo4j.GraphDatabaseService()
3 node=graph.create({"name":'James'},{'name':'Julie'})
----> 4 rel=graph.create((james,"knows",julie))
NameError: name 'james' is not defined
此外,如果我使用 rexster
而不是 neo4j
,我也会遇到与 bulbs
相同的错误,即
>>> from bulbs.rexster import Graph
>>> g = Graph()
>>> g.vertices.create(name="James")
>>> g.vertices.create(name="Julie")
>>> g.edges.create(james, "knows", julie)
---------------------------------------------------------------------------
NameError Traceback (most recent call last)
<ipython-input-6-2cfb5faa42d1> in <module>()
3 g.vertices.create(name="James")
4 g.vertices.create(name="Julie")
----> 5 g.edges.create((james, "knows", julie))
NameError: name 'james' is not defined
这里出了什么问题?
谢谢
最佳答案
仅通过创建具有类似 name
属性的节点,不会自动创建应用程序变量 james
和 julie
。您尚未分享任何 py2neo 代码,而且我对灯泡不熟悉,但在 py2neo 中您需要执行以下操作:
from py2neo import neo4j
graph_db = neo4j.GraphDatabaseService()
james, julie = graph_db.create(node(name="James"), node(name="Julie"))
graph_db.create(rel(james, "KNOWS", julie))
如果您愿意,您当然可以在同一个语句(和批处理)中创建节点和关系:
from py2neo import neo4j
graph_db = neo4j.GraphDatabaseService()
james, julie, friendship = graph_db.create(
node(name="James"), node(name="Julie"), rel(0, "KNOWS", 1)
)
关于python - 无法在Python中重现灯泡/py2neo来创建边缘(关系),我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/16250928/