Having no keyring backends should be treated as no keyring module and fall back to using memory-based cache

[gerilya]

Expected behavior

If an attempt to load keyring module fails, there is a fall back to _OAuth2TokenInMemoryCache.
I think no backends or having keyring.backends.null.Keyring backend should be treated the same way.
Using keyring.backends.null.Keyring backend is the recommended way to disable keyring. See Disabling Keyring at https://pypi.org/project/keyring/

Actual behavior

When there is keyring package installed but there are no available backends, the following error is generated:

Although keyring module is installed no backend has been detected, check https://pypi.org/project/keyring/ for more information.

Steps To Reproduce

Run the following code on Sagemaker notebook instance:

import trino

connect = trino.dbapi.connect(
                              host=config['HOST'],
                              port=config['PORT'],
                              http_scheme=config['PROTOCOL'],
                              auth=trino.auth.OAuth2Authentication(),
                              user=config['USERNAME'],
                              )
cursor=connect.cursor()
query="some query"
cursor.execute(query)

Log output

[ 2023-12-14T09:53:41.370244 | Although keyring module is installed no backend has been detected, check https://pypi.org/project/keyring/ for more information. ]

Operating System

AWS Sagemaker Notebook

Trino Python client version

0.327.0

Trino Server version

can't connect - not relevant

Python version

Python 3.10.13

Are you willing to submit PR?

• Yes I am willing to submit a PR!

[hashhar]

@hovaesco can this be closed after #435?

[hovaesco]

@hashhar Yes.

[hovaesco]

Resolved by #435