User helpers

Helpers that authenticate as you: in a JupyterHub notebook, on a laptop, or in any other code you run yourself. databaas_utils.notebook is the module's former name and still works as an alias.

databaas_utils.user

One-line entry points that authenticate as the person running the code.

Mirrors databaas_utils.airflow's helpers, but the identity is the user, not a pipeline's service account:

inside a JupyterHub singleuser pod, the token the hub mints for the logged-in user (LakehouseSettings.from_jupyterhub);
anywhere else (a laptop notebook, a script, a local app), the session saved by databaas login (LakehouseSettings.from_profile).

So the same code runs unchanged on the platform and on a laptop. DAGs must not use this module: a task authenticates through its Airflow connection.

get_settings

get_settings(
    *,
    namespace: str | None = None,
    warehouse: str | None = None,
    profile: str | None = None,
) -> LakehouseSettings

Settings for the current user.

An explicit profile always means the databaas login session, even inside JupyterHub.

Parameters:

Name	Type	Description	Default
`namespace`	`str \| None`	Default namespace for tables and generic tables.	`None`
`warehouse`	`str \| None`	Overrides the warehouse.	`None`
`profile`	`str \| None`	A `databaas login` profile name. Forces the local session.	`None`

Raises:

Type	Description
`ConfigurationError`	Outside JupyterHub, if no `databaas login` profile exists.
`AuthenticationError`	If a token cannot be obtained.

Example

settings = get_settings(namespace="knmi")

get_catalog

get_catalog(
    *,
    warehouse: str | None = None,
    profile: str | None = None,
    **overrides: str,
) -> Catalog

A pyiceberg REST catalog, signing through Lakekeeper.

Use fully qualified namespace.table identifiers with it. Needs the iceberg extra.

Parameters:

Name	Type	Description	Default
`warehouse`	`str \| None`	Overrides the warehouse.	`None`
`profile`	`str \| None`	A `databaas login` profile name. Forces the local session.	`None`
`**overrides`	`str`	pyiceberg catalog properties that replace the defaults.	`{}`

Example

catalog = get_catalog() catalog.load_table("open_meteo.daily_summary").scan(limit=10).to_arrow()

get_store

get_store(
    *,
    namespace: str | None = None,
    warehouse: str | None = None,
    profile: str | None = None,
) -> GenericTableStore

Files under generic tables in namespace, on remote-signed storage.

Needs the obstore extra.

Parameters:

Name	Type	Description	Default
`namespace`	`str \| None`	Namespace holding the generic tables.	`None`
`warehouse`	`str \| None`	Overrides the warehouse.	`None`
`profile`	`str \| None`	A `databaas login` profile name. Forces the local session.	`None`

Example

store = get_store(namespace="knmi") store.get("harmonie", "2026/09/30/run.grib2", Path("run.grib2"))

get_index

get_index(
    *,
    namespace: str | None = None,
    table: str = "files",
    warehouse: str | None = None,
    profile: str | None = None,
) -> FileIndex

The Iceberg index of what landed in namespace's generic tables.

Parameters:

Name	Type	Description	Default
`namespace`	`str \| None`	Namespace holding the index table.	`None`
`table`	`str`	Index table name.	`'files'`
`warehouse`	`str \| None`	Overrides the warehouse.	`None`
`profile`	`str \| None`	A `databaas login` profile name. Forces the local session.	`None`

Example

get_index(namespace="knmi").scan(limit=10)

get_zarr_group

get_zarr_group(
    table: str,
    *,
    namespace: str | None = None,
    path: str = "",
    read_only: bool = False,
    create: bool = True,
    doc: str = "Zarr store",
    warehouse: str | None = None,
    profile: str | None = None,
) -> Group

A zarr group stored under the generic table namespace.table.

Needs the zarr extra. Opening for write creates the table if missing, so pass read_only=True when you only want to look.

Parameters:

Name	Type	Description	Default
`table`	`str`	Generic table holding the zarr store.	required
`namespace`	`str \| None`	Namespace holding the table.	`None`
`path`	`str`	Group path within the store.	`''`
`read_only`	`bool`	Open for reading only.	`False`
`create`	`bool`	Create the table and group if missing (ignored if `read_only`).	`True`
`doc`	`str`	Description recorded on a newly created table.	`'Zarr store'`
`warehouse`	`str \| None`	Overrides the warehouse.	`None`
`profile`	`str \| None`	A `databaas login` profile name. Forces the local session.	`None`

Example

group = get_zarr_group("harmonie_zarr", namespace="knmi", read_only=True) list(group.keys())