Provide a way to override requested scopes

[tswast]

Additional scopes are required when using BigQuery to access external data sources such as Google Drive or Bigtable.

It looks like the GbqConnector class currently only uses the https://www.googleapis.com/auth/bigquery scope and does not override the scopes in the constructor.

[ghost]

Well, it's not Pandas-GoogleBigQuery package then anymore. Bigtable API has very different schema, and for drive I cannot see any general use case for getting data to a pandas DF.

[tswast]

@mremes You can query those data sources using the BigQuery API, you just need to create an external data source in BigQuery and have the right scopes.

[ghost]

Yup, sorry my bad! :)

[LauraRichter]

Hi. I'm having this same issue. I'e created an external bq data source that links to a google sheet. But reading it in with pd.read_gbq gives "BigQuery BigQuery: No OAuth token with Google Drive scope was found."
If not in pandas_gbq, where should the drive scope be set? Or are you saying that pandas_gbq shouldn't be used for this at all?

[tswast]

Pandas-GBQ does not yet support scopes other than BigQuery. If someone were to work on this feature request, there are several ways credentials can be fetched, so there are several places to update.

• Application Default Credentials

  https://github.com/pydata/pandas-gbq/blob/79c90677860d793626344aada7315ab6727b45aa/pandas_gbq/gbq.py#L251

• User credentials

  https://github.com/pydata/pandas-gbq/blob/79c90677860d793626344aada7315ab6727b45aa/pandas_gbq/gbq.py#L356

• Service account credentials

  https://github.com/pydata/pandas-gbq/blob/79c90677860d793626344aada7315ab6727b45aa/pandas_gbq/gbq.py#L393

[tswast]

I have accounted for this feedback in my auth proposal at #161.

I hope to add a new pandas_gbq.get_user_credentials() function which takes a scopes argument. Closing this issue as a duplicate of #161.