py2neo create keyError

Question

I'm a newbe with py2neo. Trying to create a KG which includes some nodes like

graph = Graph('http://127.0.0.1:7474/', name="test", password="12345678")
node1 = Node('Person', name='Bob')
graph.create(node1)

but I'm getting a KeyError: 'location', in detail:

Traceback (most recent call last):
  File "D:\PyCharm-workspace\learn_Neo4j\test.py", line 23, in <module>
    graph.create(node4)
  File "D:\python3.8\lib\site-packages\py2neo\database.py", line 591, in create
    self.update(lambda tx: tx.create(subgraph))
  File "D:\python3.8\lib\site-packages\py2neo\database.py", line 445, in update
    self._update(cypher, timeout=timeout)
  File "D:\python3.8\lib\site-packages\py2neo\database.py", line 467, in _update
    tx = self.begin(
  File "D:\python3.8\lib\site-packages\py2neo\database.py", line 351, in begin
    return Transaction(self, autocommit=False, readonly=readonly,
  File "D:\python3.8\lib\site-packages\py2neo\database.py", line 915, in __init__
    self._ref = self._connector.begin(self.graph.name, readonly=readonly,
  File "D:\python3.8\lib\site-packages\py2neo\client\__init__.py", line 1359, in begin
    return cx.begin(graph_name, readonly=readonly,
  File "D:\python3.8\lib\site-packages\py2neo\client\http.py", line 200, in begin
    location_path = urlsplit(r.headers["Location"]).path
  File "D:\python3.8\lib\site-packages\urllib3\_collections.py", line 157, in __getitem__
    val = self._container[key.lower()]
KeyError: 'location'

Here are the whole codes:

from py2neo import Graph, Node, Relationship, NodeMatcher


graph = Graph('http://127.0.0.1:7474/', name="test", password="12345678")

node1 = Node('Person', name='Bob')
node2 = Node('Person', name='Alice')
node3 = Node('animal', name='cat')
node4 = Node('animal', name='dog')

r1 = Relationship(node2, 'know', node1)
r2 = Relationship(node1, 'know', node3)
r3 = Relationship(node2, 'has', node3)
r4 = Relationship(node2, 'has', node4)

graph.create(node1)
graph.create(node2)
graph.create(node3)
graph.create(node4)
graph.create(r1)
graph.create(r2)
graph.create(r3)
graph.create(r4)

matcher = NodeMatcher(graph)
print(list(matcher.match('animal')))

Please tell me the reason, thank you in advance.

Answer 1

Your code works well when I run it so something is not working on your neo4j server when calling it. Below is the code from py2neo http.py ("D:\python3.8\lib\site-packages\py2neo\client\http.py")

               # connecting to your graph
198            r = self._post(HTTPTransactionRef.begin_uri(graph_name))
               # converting the response into json format
199            rs = HTTPResponse.from_json(r.status, r.data.decode("utf-8"))
               # get the path of the header location
200            location_path = urlsplit(r.headers["Location"]).path

Thus the http response has no header location, and raising an error.

Try using http://localhost:7474/ instead of http://127.0.0.1:7474/.