Can arg "auth" of GraphDatabase.driver accept an array?

[Bill-XU]

Hello,

I want to create a neo4j driver by passing args loaded from a TOML.

CREATE_DRIVER = lambda: GraphDatabase.driver(**load_db_config())

But I found that drivers created from this always throw an error "Unable to retrieve routing information".
I tried to find the reason, and got this.

1. When passing tuple to auth, it works fine.

with GraphDatabase.driver(uri="neo4j://localhost:7687", auth=("neo4j", "neo4j")) as drv:
    drv.verify_connectivity() # Works fine

2. But, when changing it to array, the error occurs.

with GraphDatabase.driver(uri="neo4j://localhost:7687", auth=["neo4j", "neo4j"]) as drv:
    drv.verify_connectivity() # Throws error "Unable to retrieve routing information"

Is it possible to let auth also accept an array?

Best regards,
Bill

[robsdedude]

Hi Bill and thanks for reaching out.

I see the use-case. However, I don't think it's particularly Pythonic (granted that assessment is opinionated). Let me quote the Python docs

https://docs.python.org/3/library/stdtypes.html#lists

Lists are mutable sequences, typically used to store collections of homogeneous items (where the precise degree of similarity will vary by application).

https://docs.python.org/3/library/stdtypes.html#tuples

Tuples are immutable sequences, typically used to store collections of heterogeneous data (such as the 2-tuples produced by the enumerate() built-in).

These design principles are also reflected in the typing system. You can annotate something with tuple[TypeA, TypeB] which specifically encodes a 2-tuple with said types. For lists, the closest you can do is list[TypeA | TypeB]. However, the latter doesn't say anything about the length of the collection, nor the order in which the types are expected.

Since the auth parameter expects exactly a 2-tuple, this is a much closer match. The fact that both items are stings is more a coincident than inherent in the design of auth tokens.

To that extend I suggest to adjust load_db_config to output auth as a tuple instead. Something like

def load_db_config():
    result = ...  # whatever you already had
    if "auth" in result:
        result["auth"] = tuple(result["auth"])
    return result

Best regards

[Bill-XU]

Thank you for the reply. Since converting lists to tuples has no downside effect on my other codes, I added a conversion for every list loaded from TOML. Now the code works fine.