Problem with creating an object in neo4j
Question: I am using the django integration for neo4j and I'm getting the following
traceback when I'm trying to create a node.  
I do have JPype installed and it can be imported.

    
    
     p = Person.objects.create(first_name='omer', last_name='katz')
    Traceback (most recent call last):
      File "<console>", line 1, in <module>
      File "/usr/local/lib/python2.7/dist-packages/django/db/models/manager.py", line 138, in create
        return self.get_query_set().create(**kwargs)
      File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/model/django_model/__init__.py", line 362, in create
        obj.save(force_insert=True)
      File "/usr/local/lib/python2.7/dist-packages/django/db/models/base.py", line 460, in save
        self.save_base(using=using, force_insert=force_insert, force_update=force_update)
      File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/_util.py", line 47, in __get__
        method, graphdb = self.descr_get(obj, cls)
      File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/_util.py", line 41, in descr_get
        graphdb = self.accessor.__get__(obj, cls)
      File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/model/django_model/__init__.py", line 58, in __get__
        return DjangoNeo.neo
      File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/model/django_model/__init__.py", line 124, in neo
        return self.__setup_neo()
      File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/model/django_model/__init__.py", line 136, in __setup_neo
        self.__neo = NeoService(resource_uri, **options)
      File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/__init__.py", line 522, in __new__
        neo = core.load_neo(resource_uri, params)
      File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/_core.py", line 180, in load_neo
        backend.initialize(**parameters)
      File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/_backend/__init__.py", line 61, in initialize
        raise ImportError("No applicable backend found.")
    ImportError: No applicable backend found.
    

EDIT:  
As requested here are my neo4j settings:

    
    
    NEO4J_RESOURCE_URI = '/var/neo4j/neo4django'
    # NEO4J_RESOURCE_URI should be the path to where
    #    you want to store the Neo4j database.
    
    NEO4J_OPTIONS = {
        # this is optional and can be used to specify
        # extra startup parameters for Neo4j, such as
        # the classpath to load Neo4j from.
    }
    

EDIT:  
After following thobe's suggestion I get the following when I try to import my
own models:

    
    
        ERROR:root:Importing native backends failed.
        Traceback (most recent call last):
          File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/_backend/__init__.py", line 51, in initialize
            embedded, remote = implementation.initialize(classpath, params)
          File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/_backend/reflection.py", line 44, in initialize
            jvm = jpype.getDefaultJVMPath()
          File "/usr/local/lib/python2.7/dist-packages/jpype/_core.py", line 96, in getDefaultJVMPath
            return _linux.getDefaultJVMPath()
          File "/usr/local/lib/python2.7/dist-packages/jpype/_linux.py", line 36, in getDefaultJVMPath
            jvm = _getJVMFromJavaHome()
          File "/usr/local/lib/python2.7/dist-packages/jpype/_linux.py", line 55, in _getJVMFromJavaHome
            if os.path.exists(java_home+"/bin/javac") :
        TypeError: unsupported operand type(s) for +: 'NoneType' and 'str'
        ERROR:root:Importing native backends failed.
        Traceback (most recent call last):
          FERROR:root:Importing native backends failed.
        Traceback (most recent call last):
          File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/_backend/__init__.py", line 51, in initialize
            embedded, remote = implementation.initialize(classpath, params)
          File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/_backend/reflection.py", line 44, in initialize
            jvm = jpype.getDefaultJVMPath()
          File "/usr/local/lib/python2.7/dist-packages/jpype/_core.py", line 96, in getDefaultJVMPath
            return _linux.getDefaultJVMPath()
          File "/usr/local/lib/python2.7/dist-packages/jpype/_linux.py", line 36, in getDefaultJVMPath
            jvm = _getJVMFromJavaHome()
          File "/usr/local/lib/python2.7/dist-packages/jpype/_linux.py", line 55, in _getJVMFromJavaHome
            if os.path.exists(java_home+"/bin/javac") :
        TypeError: unsupported operand type(s) for +: 'NoneType' and 'str'
        ERROR:root:Importing native backends failed.
        Traceback (most recent call last):
          File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/_backend/__init__.py", line 51, in initialize
            embedded, remote = implementation.initialize(classpath, params)
          File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/_backend/reflection.py", line 44, in initialize
            jvm = jpype.getDefaultJVMPath()
          File "/usr/local/lib/python2.7/dist-packages/jpype/_core.py", line 96, in getDefaultJVMPath
            return _linux.getDefaultJVMPath()
          File "/usr/local/lib/python2.7/dist-packages/jpype/_linux.py", line 36, in getDefaultJVMPath
            jvm = _getJVMFromJavaHome()
          File "/usr/local/lib/python2.7/dist-packages/jpype/_linux.py", line 55, in _getJVMFromJavaHome
            if os.path.exists(java_home+"/bin/javac") :
        TypeError: unsupported operand type(s) for +: 'NoneType' and 'str'
        ERROR:root:Importing native backends failed.
        Traceback (most recent call last):
          File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/_backend/__init__.py", line 51, in initialize
            embedded, remote = implementation.initialize(classpath, params)
          File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/_backend/reflection.py", line 44, in initialize
            jvm = jpype.getDefaultJVMPath()
          File "/usr/local/lib/python2.7/dist-packages/jpype/_core.py", line 96, in getDefaultJVMPath
            return _linux.getDefaultJVMPath()
          File "/usr/local/lib/python2.7/dist-packages/jpype/_linux.py", line 36, in getDefaultJVMPath
            jvm = _getJVMFromJavaHome()
          File "/usr/local/lib/python2.7/dist-packages/jpype/_linux.py", line 55, in _getJVMFromJavaHome
            if os.path.exists(java_home+"/bin/javac") :
        TypeError: unsupported operand type(s) for +: 'NoneType' and 'str'
        ERROR:root:Importing native backends failed.
        Traceback (most recent call last):
          File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/_backend/__init__.py", line 51, in initialize
            embedded, remote = implementation.initialize(classpath, params)
          File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/_backend/reflection.py", line 44, in initialize
            jvm = jpype.getDefaultJVMPath()
          File "/usr/local/lib/python2.7/dist-packages/jpype/_core.py", line 96, in getDefaultJVMPath
            return _linux.getDefaultJVMPath()
          File "/usr/local/lib/python2.7/dist-packages/jpype/_linux.py", line 36, in getDefaultJVMPath
            jvm = _getJVMFromJavaHome()
          File "/usr/local/lib/python2.7/dist-packages/jpype/_linux.py", line 55, in _getJVMFromJavaHome
            if os.path.exists(java_home+"/bin/javac") :
        TypeError: unsupported operand type(s) for +: 'NoneType' and 'str'
        ERROR:root:Importing native backends failed.
        Traceback (most recent call last):
          File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/_backend/__init__.py", line 51, in initialize
            embedded, remote = implementation.initialize(classpath, params)
          File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/_backend/reflection.py", line 44, in initialize
            jvm = jpype.getDefaultJVMPath()
          File "/usr/local/lib/python2.7/dist-packages/jpype/_core.py", line 96, in getDefaultJVMPath
            return _linux.getDefaultJVMPath()
          File "/usr/local/lib/python2.7/dist-packages/jpype/_linux.py", line 36, in getDefaultJVMPath
            jvm = _getJVMFromJavaHome()
          File "/usr/local/lib/python2.7/dist-packages/jpype/_linux.py", line 55, in _getJVMFromJavaHome
            if os.path.exists(java_home+"/bin/javac") :
        TypeError: unsupported operand type(s) for +: 'NoneType' and 'str'
    
    ile "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/_backend/__init__.py", line 51, in initialize
        embedded, remote = implementation.initialize(classpath, params)
      File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/_backend/reflection.py", line 44, in initialize
        jvm = jpype.getDefaultJVMPath()
      File "/usr/local/lib/python2.7/dist-packages/jpype/_core.py", line 96, in getDefaultJVMPath
        return _linux.getDefaultJVMPath()
      File "/usr/local/lib/python2.7/dist-packages/jpype/_linux.py", line 36, in getDefaultJVMPath
        jvm = _getJVMFromJavaHome()
      File "/usr/local/lib/python2.7/dist-packages/jpype/_linux.py", line 55, in _getJVMFromJavaHome
        if os.path.exists(java_home+"/bin/javac") :
    TypeError: unsupported operand type(s) for +: 'NoneType' and 'str'
    ERROR:root:Importing native backends failed.
    Traceback (most recent call last):
      File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/_backend/__init__.py", line 51, in initialize
        embedded, remote = implementation.initialize(classpath, params)
      File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/_backend/reflection.py", line 44, in initialize
        jvm = jpype.getDefaultJVMPath()
      File "/usr/local/lib/python2.7/dist-packages/jpype/_core.py", line 96, in getDefaultJVMPath
        return _linux.getDefaultJVMPath()
      File "/usr/local/lib/python2.7/dist-packages/jpype/_linux.py", line 36, in getDefaultJVMPath
        jvm = _getJVMFromJavaHome()
      File "/usr/local/lib/python2.7/dist-packages/jpype/_linux.py", line 55, in _getJVMFromJavaHome
        if os.path.exists(java_home+"/bin/javac") :
    TypeError: unsupported operand type(s) for +: 'NoneType' and 'str'
    ERROR:root:Importing native backends failed.
    Traceback (most recent call last):
      File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/_backend/__init__.py", line 51, in initialize
        embedded, remote = implementation.initialize(classpath, params)
      File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/_backend/reflection.py", line 44, in initialize
        jvm = jpype.getDefaultJVMPath()
      File "/usr/local/lib/python2.7/dist-packages/jpype/_core.py", line 96, in getDefaultJVMPath
        return _linux.getDefaultJVMPath()
      File "/usr/local/lib/python2.7/dist-packages/jpype/_linux.py", line 36, in getDefaultJVMPath
        jvm = _getJVMFromJavaHome()
      File "/usr/local/lib/python2.7/dist-packages/jpype/_linux.py", line 55, in _getJVMFromJavaHome
        if os.path.exists(java_home+"/bin/javac") :
    TypeError: unsupported operand type(s) for +: 'NoneType' and 'str'
    ERROR:root:Importing native backends failed.
    Traceback (most recent call last):
      File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/_backend/__init__.py", line 51, in initialize
        embedded, remote = implementation.initialize(classpath, params)
      File "/usr/local/lib/python2.7/dist-packages/Neo4j.py-0.1_SNAPSHOT-py2.7.egg/neo4j/_backend/reflection.py", line 44, in initialize
        jvm = jpype.getDefaultJVMPath()
      File "/usr/local/lib/python2.7/dist-packages/jpype/_core.py", line 96, in getDefaultJVMPath
        return _linux.getDefaultJVMPath()
      File "/usr/local/lib/python2.7/dist-packages/jpype/_linux.py", line 36, in getDefaultJVMPath
        jvm = _getJVMFromJavaHome()
      File "/usr/local/lib/python2.7/dist-packages/jpype/_linux.py", line 55, in _getJVMFromJavaHome
        if os.path.exists(java_home+"/bin/javac") :
    TypeError: unsupported operand type(s) for +: 'NoneType' and 'str'
    


Answer: You can get more verbose information about why the backend couldn't be found
by adding this to NEO4J_OPTIONS:

    
    
    NEO4J_OPTIONS = {
        log: True,
    }
    

The output from that logging will make it easier to diagnose the actual issue
and suggest a fix.

