[Feature Request]: Neo4jGraphstore and Neo4jVectorstore should expose the python driver as a parameter to enable users to pass in their own neo4j driver instances

[Sauti-AI]

Feature Description

Currently, the code base does not allow a user of these abstractions to pass in a driver:
class Neo4jGraphStore(GraphStore):
def init(
self,
username: str,
password: str,
url: str,
database: str = "neo4j",
node_label: str = "Entity",
**kwargs: Any,
) -> None:
self.node_label = node_label
self._driver = neo4j.GraphDatabase.driver(url, auth=(username, password))
self._database = database
self.schema = ""
self.structured_schema: Dict[str, Any] = {}
# Verify connection
try:
with self._driver as driver:
driver.verify_connectivity()
except neo4j.exceptions.ServiceUnavailable:
raise ValueError(
"Could not connect to Neo4j database. "
"Please ensure that the url is correct"
)
except neo4j.exceptions.AuthError:
raise ValueError(
"Could not connect to Neo4j database. "
"Please ensure that the username and password are correct"
)

This could instead be:
class Neo4jGraphStore(GraphStore):
def init(
self,
database: str = "neo4j",
node_label: str = "Entity",
username: Optional[str] = None,
password: Optional[str] = None,
url: Optional[str] = None,
driver: Optional[Any] = None,
**kwargs: Any,
) -> None:
self.node_label = node_label
// No validations but just to illustrate the concept.
self._driver = driver or neo4j.GraphDatabase.driver(url, auth=(username, password))
self._database = database
self.schema = ""
self.structured_schema: Dict[str, Any] = {}
# Verify connection
try:
with self._driver as driver:
driver.verify_connectivity()
except neo4j.exceptions.ServiceUnavailable:
raise ValueError(
"Could not connect to Neo4j database. "
"Please ensure that the url is correct"
)
except neo4j.exceptions.AuthError:
raise ValueError(
"Could not connect to Neo4j database. "
"Please ensure that the username and password are correct"
)

I observed the same issue for the Neo4jVectorStore:

class Neo4jVectorStore(VectorStore):
"""Neo4j Vector Store.

Examples:
    `pip install llama-index-vector-stores-neo4jvector`


    ```python
    from llama_index.vector_stores.neo4jvector import Neo4jVectorStore

    username = "neo4j"
    password = "pleaseletmein"
    url = "bolt://localhost:7687"
    embed_dim = 1536

    neo4j_vector = Neo4jVectorStore(username, password, url, embed_dim)
    ```
"""

stores_text: bool = True
flat_metadata = True

def __init__(
    self,
    username: str,
    password: str,
    url: str,
    embedding_dimension: int,
    database: str = "neo4j",
    index_name: str = "vector",
    keyword_index_name: str = "keyword",
    node_label: str = "Chunk",
    embedding_node_property: str = "embedding",
    text_node_property: str = "text",
    distance_strategy: str = "cosine",
    hybrid_search: bool = False,
    retrieval_query: str = "",
    **kwargs: Any,
) -> None:
    if distance_strategy not in ["cosine", "euclidean"]:
        raise ValueError("distance_strategy must be either 'euclidean' or 'cosine'")

    self._driver = neo4j.GraphDatabase.driver(url, auth=(username, password))
    self._database = database

    # Verify connection
    try:
        self._driver.verify_connectivity()
    except neo4j.exceptions.ServiceUnavailable:
        raise ValueError(
            "Could not connect to Neo4j database. "
            "Please ensure that the url is correct"
        )
    except neo4j.exceptions.AuthError:
        raise ValueError(
            "Could not connect to Neo4j database. "
            "Please ensure that the username and password are correct"
        )

Reason

As it is right now, the driver instance is tightly coupled to the node_label. If I am to use this abstraction, for each node_label, I would need to create a new Neo4jGraphStore object. Is this correct?

Value of Feature

Remove coupling between the neo4j driver and the node_label and make the abstraction more adaptable.

[gich2009]

I have observed this too. Is there a reason why the driver is not exposed as a parameter?