Deprecation warning when using rest dialect with sqlalchemy

[aclemons]

Overview

I am using PyAthena 3.13.0 with sqlalchemy 2.0.40 and there is a deprecation warning regarding a missing class method on AthenaRestDialect:

sqlalchemy.exc.SADeprecationWarning: The dbapi() classmethod on dialect classes has been renamed to import_dbapi().  Implement an import_dbapi() classmethod directly on class <class 'pyathena.sqlalchemy.rest.AthenaRestDialect'> to remove this warning; the old .dbapi() classmethod may be maintained for backwards compatibility.

It looks like sqlalchemy requires the method on the parent to be directly on the class and not the parent:

https://github.com/laughingman7743/PyAthena/blob/d2806e4668ee9e718d35c22eee21a383edfc2e5a/pyathena/sqlalchemy/base.py#L1011-L1013

Here is the checking code in sqlalchemy:

https://github.com/sqlalchemy/sqlalchemy/blob/396c3fc70f36923c886e4fd45bc47f764cbd3245/lib/sqlalchemy/engine/create.py#L577-L602

[laughingman7743]

#528

[aclemons]

@laughingman7743, thank you for checking the issue, but could please check again.

Sorry, I think I was not clear in the description of the ticket. I've read both of those linked tickets and I don't want to remove 1.4 compatibility, it is just that the class method used by v2 is in the wrong place for sqlalchemy to find it.

This commit added this method initially:

e53908c

but this broke compatibility with 1.4 so the old method was added back in

4b40732

That's all fine.

But the v2 method needs to be on the child engine classes for sqlalchemy to find it to avoid the if/else block I linked to above.

https://github.com/sqlalchemy/sqlalchemy/blob/396c3fc70f36923c886e4fd45bc47f764cbd3245/lib/sqlalchemy/engine/create.py#L577-L602

[aclemons]

The check done by sqlalchemy:

$ uv run python3
Python 3.13.3 (main, May  7 2025, 10:15:51) [GCC 14.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from pyathena.sqlalchemy.rest import AthenaRestDialect
>>> "import_dbapi" in AthenaRestDialect.__dict__
False

If the classmethod moves to AthenaRestDialect / AthenaPandasDialect, there is no deprecation warning.

[laughingman7743]

https://github.com/laughingman7743/PyAthena/blob/master/pyathena/sqlalchemy/base.py#L1011-L1013
Does this mean that this implementation is not working correctly? 🤔

[aclemons]

I don't think it is - I think sqlalchemy 2 is just falling back and using the dbapi method.

[laughingman7743]

It seems necessary to define the import_dbapi method in classes that inherit AthenaDialect.
#584
This change ensures that the WARNING message will no longer be displayed.