py2neo图查询中的ValueError

Question

我正试着在python中用neo4j做一个简单的图形查询。我的查询如下所示

def do_query(self):
    graph = Graph(settings.NEO4J_CONNECTION_STRING)

    query = 'MATCH (n:SomeNode) WHERE n.id = ' + id + ' RETURN n'
    data = graph.cypher.execute(query)

但是，当我在Django REST处理程序中运行它时，我得到以下错误

Traceback (most recent call last):
File "/Users/me/.virtualenvs/app/lib/python2.7/site-packages/django/core/handlers/base.py", line 149, in get_response
response = self.process_exception_by_middleware(e, request)
File "/Users/me/.virtualenvs/app/lib/python2.7/site-packages/django/core/handlers/base.py", line 147, in get_response
response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/Users/me/.virtualenvs/app/lib/python2.7/site-packages/django/views/decorators/csrf.py", line 58, in wrapped_view
return view_func(*args, **kwargs)
File "/Users/me/.virtualenvs/app/lib/python2.7/site-packages/django/views/generic/base.py", line 68, in view
return self.dispatch(request, *args, **kwargs)
File "/Users/me/.virtualenvs/app/lib/python2.7/site-packages/rest_framework/views.py", line 466, in dispatch
response = self.handle_exception(exc)
File "/Users/me/.virtualenvs/app/lib/python2.7/site-packages/rest_framework/views.py", line 463, in dispatch
response = handler(request, *args, **kwargs)
File "/Users/me/Development/app/search/api/views.py", line 351, in get
results = graph_queries.do_query(user_id)
File "/Users/me/Development/app/app/graph_queries.py", line 43, in do_query
data = graph.cypher.execute(query)
File "/Users/me/.virtualenvs/app/lib/python2.7/site-packages/py2neo/core.py", line 661, in cypher
metadata = self.resource.metadata
File "/Users/me/.virtualenvs/app/lib/python2.7/site-packages/py2neo/core.py", line 213, in metadata
self.get()
File "/Users/me/.virtualenvs/app/lib/python2.7/site-packages/py2neo/core.py", line 258, in get
response = self.__base.get(headers=headers, redirect_limit=redirect_limit, **kwargs)
File "/Users/me/.virtualenvs/app/lib/python2.7/site-packages/py2neo/packages/httpstream/http.py", line 966, in get
return self.__get_or_head("GET", if_modified_since, headers, redirect_limit, **kwargs)
File "/Users/me/.virtualenvs/app/lib/python2.7/site-packages/py2neo/packages/httpstream/http.py", line 943, in __get_or_head
return rq.submit(redirect_limit=redirect_limit, **kwargs)
File "/Users/me/.virtualenvs/app/lib/python2.7/site-packages/py2neo/packages/httpstream/http.py", line 433, in submit
http, rs = submit(self.method, uri, self.body, self.headers)
File "/Users/me/.virtualenvs/app/lib/python2.7/site-packages/py2neo/packages/httpstream/http.py", line 302, in submit
raise ValueError("Unsupported URI scheme " + repr(uri.scheme))
ValueError: Unsupported URI scheme None

我真的不确定从哪里开始。我非常确信到Neo4J的连接是良好的，并且处理程序被正确调用，如回溯中所示。我的查询有什么问题吗？

Answer 1

原来问题是我使用的是import settings而不是from django.conf import settings，这意味着我没有读取正确的设置。