我在与Neo4j使用Neomodel和py2neo客户端时遇到了一些问题。我在单独的anaconda虚拟环境中安装了Neomodel和py2neo,并分别进行了测试。 Neo4j使用docker安装/停靠。
Neomodel
代码
from neomodel import (config, StructuredNode, StringProperty, IntegerProperty,UniqueIdProperty, RelationshipTo, RelationshipFrom)
config.DATABASE_URL = 'bolt://neo4j:password@localhost:7687'
class Country(StructuredNode):
code = StringProperty(unique_index=True, required=True)
# traverse incoming IS_FROM relation, inflate to Person objects
inhabitant = RelationshipFrom('Person', 'IS_FROM')
class Person(StructuredNode):
uid = UniqueIdProperty()
name = StringProperty(unique_index=True)
age = IntegerProperty(index=True, default=0)
# traverse outgoing IS_FROM relations, inflate to Country objects
country = RelationshipTo(Country, 'IS_FROM')
jim = Person(name='Jim', age=3).save()
jim.age = 4
jim.save() # validation happens here
jim.delete()
jim.refresh() # reload properties from neo
jim.id # neo4j internal id
Neomodel生成在neo4j webapp上查看的节点。创建的节点是Jim,年龄= 3,即它似乎没有记录Jims年龄从3 - > 4变化的事实。另外,我假设jim.delete()会删除它既没有删除的节点。最后,它会提示以下错误(下面是错误最后几行的片段)。
错误
...
File "/Users/sjamal/.conda/envs/tneo/lib/python3.6/site-
packages/neomodel/core.py", line 452, in inflate
if db_property in node.properties:
AttributeError: 'Node' object has no attribute 'properties'
现在我确实找到了这个帖子,其中用户“杰克丹尼尔”提到neomodel不支持neo4j 3.所以我尝试对接Neo4j v.2.3图像,但后来我收到以下错误(请注意它是最后几行的片段错误)
对接图像Neo4j 2.3时出错
File "/Users/sjamal/.conda/envs/tneo/lib/python3.6/ssl.py", line 817, in __init__
self.do_handshake()
File "/Users/sjamal/.conda/envs/tneo/lib/python3.6/ssl.py", line 1077, in do_handshake
self._sslobj.do_handshake()
File "/Users/sjamal/.conda/envs/tneo/lib/python3.6/ssl.py", line 689, in do_handshake
self._sslobj.do_handshake()
OSError: [Errno 0] Error
Py2neo
由于Neomodel遇到的问题,我开始考虑使用p2neo,但我似乎无法正确配置。
代码
from py2neo import Node, Relationship, Graph
graph = Graph("localhost", user='neo4j', password='password', bolt=None)
alice = Node("Person", name="Alice")
bob = Node("Person", name="Bob")
alice_knows_bob = Relationship(alice, "KNOWS", bob)
graph.create(alice_knows_bob)
错误
File "/Users/sjamal/.conda/envs/py2neo_test/lib/python3.6/site-packages/neo4j/bolt/connection.py", line 459, in acquire
connection = self.connector(address)
File "/Users/sjamal/.conda/envs/py2neo_test/lib/python3.6/site-packages/neo4j/v1/bolt.py", line 46, in <lambda>
pool = ConnectionPool(lambda a: connect(a, security_plan.ssl_context, **config))
File "/Users/sjamal/.conda/envs/py2neo_test/lib/python3.6/site-packages/neo4j/bolt/connection.py", line 601, in connect
raise ProtocolError("Connection to %r closed without handshake response" % (address,))
neo4j.bolt.connection.ProtocolError: Connection to ('localhost', 7687) closed without handshake response
感谢任何人对此进行调查。我很乐意收到关于如何设置Py2neo的任何建议或解释,无论我是否让Neomodel工作。
所以我设法用Py2neo解决了我的问题,但没有解决我与Neomodel的问题。如果我确实找到了让Neomodel工作的方法,我会发布它并链接到这篇帖子或在这个帖子中发表评论。
P2neo解决方案与p2neo hf.0和neochy uz.o相关
我尝试了各种组合,从neo4j 2.3开始,连同不同版本的py2neo,如3.1.2,然后用neo4j v3.0做同样的事情。
我正在发布我用于创建节点和图形连接的脚本,因为我在试图弄清楚我是否设置配置不佳或包装,驱动程序等中存在错误时会发疯。
Py2neo脚本
from py2neo import Node, Relationship, Graph
graph = Graph('http://localhost:7474/db/data',user='neo4j',pass word='password1234')
tx = graph.begin()
a = Node(label='hero',name='Sabri')
tx.create(a)
tx.commit()
过时的驱动程序py2neo v3.1.2与Neo4j v3.4串联
正如本Github问题报告https://github.com/neo4j/neo4j-python-driver/issues/252中所讨论的,报告该问题的用户正在使用py2neo 3.1.2和Neo4jv3.4。怀疑是由于py2neo 3.1.2附带的过时驱动程序(v1.1)。 Neo4j v3.4的新发行版似乎附带了新的驱动程序1.6。
将py2neo升级到v4.0并坚持使用最新版本的Neo4j服务器,即v3.4
这样做时我遇到了一个不同的错误
File "/Users/sjamal/.conda/envs/py2neo.v4/lib/python3.6/site-packages/py2neo/internal/http.py", line 26, in <module>
from neo4j.addressing import SocketAddress
ModuleNotFoundError: No module named 'neo4j.addressing'
在这个stackoverflow线程(ModuleNotFoundError: No module named 'neo4j.addressing' and ModuleNotFoundError: No module named 'neo4j')中讨论过,问题可能是驱动程序1.6驱动程序可能必须通过pip手动安装,我这样做了。
pip install neo4j-driver==1.6.2
我现在收到一个新错误,其中在调用map对象时捕获了TypeError。
File "/Users/sjamal/.conda/envs/py2neo.v4/lib/python3.6/site-packages/py2neo/internal/http.py", line 74, in fix_parameters
raise TypeError("Parameters of type {} are not supported".format(type(value).__name__))
TypeError:不支持类型为map的参数
我发现speters-cmri https://github.com/technige/py2neo/issues/688发布了这个github问题,它包含以下github提交(https://github.com/technige/py2neo/compare/v4...CMRI-ProCan:v4),通过修改py2neo包中的json.py脚本来解决问题
我再次运行我的脚本来添加测试节点,它运行没有任何问题。
如果你太懒或太沮丧而无法通过长篇解释这里是一个总结
1. Make sure neo4j v3.0+ is installed. I suggest you look into docker to install neo4j using a docker image
2. pip install py2neo==v4.0
3. pip install neo4j-driver==1.6.2
4. Modify json.py file as described here https://github.com/technige/py2neo/compare/v4...CMRI-ProCan:v4
5. Run py2neo script outlined above