How to include catalogs with assets containing multiple variables as a nested catalog

[dougiesquire]

I'd like to set up a catalog of intake-esm catalogs, e.g. a catalog.yaml file something like:

plugins:
  source:
  - module: intake_xarray
  - module: intake_esm

sources:
  esm_catalog_0:
    args:
      obj: /path/to/esm_catalog_0.json
    driver: intake_esm.esm_datastore
    metadata: {}
  esm_catalog_1:
    args:
      obj: /path/to/esm_catalog_1.json
    driver: intake_esm.esm_datastore
    metadata: {}

However, my intake-esm catalogs have assets containing multiple variables. This require passing a function as an argument which I can't do with my catalog.yaml.

Is it possible to set up a catalog of nested intake-esm catalogs with multi-variable assets that works by default? I'm aware I can pass the read_csv_kwargs when querying the catalog as follows, but it would be nicer if this could be configured in catalog.yaml:

cat = intake.open_catalog("catalog.yaml")
esm_catalog_0 = cat.esm_catalog_0(
    read_csv_kwargs={"converters": {"variable": ast.literal_eval}}
)

If this is not possible, is there interested in making it possible (e.g., by adding a boolean parameter multi_variable_assets to the intake_esm.core.esm_datastore API)?

[dougiesquire]

In #589, we added an optional columns_with_iterables parameter to intake_esm.esm_datastore that specifies the columns to convert with ast.literal_eval.