z3fdb.simple_store_builder

Classes

SimpleStoreBuilder

Builder to create a Zarr store with FDB backing.

Module Contents

class SimpleStoreBuilder(fdb_config_file: pathlib.Path | None = None)

Builder to create a Zarr store with FDB backing.

This builder will create a Zarr store with a Zarr Array at its root (“/”) containing the data from your MARS request(s).

It is exactly CustomStoreBuilder restricted to the root array, and delegates to it – so the two cannot drift apart.

Parameters:

fdb_config_file – Optional path to FDB config file. If not set normal FDB config file resolution is applied.

_builder

add_part(mars_request: pychunked_data_view.MarsSelection, axes: list[pychunked_data_view.AxisDefinition], extractor: pychunked_data_view.ExtractorType.Grib | pychunked_data_view.ExtractorType.GribJump) → None

Add a MARS request to the view.

Parameters:

• mars_request (MarsSelection) –

  A dict mapping MARS keys to their values. Single values may be given as str, int, or float; multi-valued keys may be given as a list. MARS range expressions (e.g. "2020-01-01/to/2020-01-04") must be passed as a plain string value.

  For example:

  {
      "type": "an",
      "class": "ea",
      "domain": "g",
      "expver": "0001",
      "stream": "oper",
      "date": "2020-01-01/to/2020-01-04",
      "levtype": "sfc",
      "step": 0,
      "param": [167, 131, 132],
      "time": "0/to/21/by/3",
  }
  

• axes (list of AxisDefinition) – List of AxisDefinitions that describe how axis in the MARS request are mapped to axis in the Zarr array.

• extractor – Extractor configuration object. Use ExtractorType.Grib() for full-field GRIB extraction or ExtractorType.GribJump(...) for partial-field extraction.

fill_missing_value(value: float) → None

Set the fill value used for bitmap-masked grid points.

Call add_part() first: this configures the array, so there has to be one.

Parameters:

value (float) – Fill value written into array positions that carry a GRIB bitmap missing flag. Also used as the zarr array fill_value.

Raises:

ValueError – If no part has been added yet.

extend_on_axis(axis: int) → None

Defines the extension axis when multiple parts are added.

Call add_part() first: this configures the array, so there has to be one.

Parameters:

axis (int) – Index of the axis that is extended when multiple parts have been added.

Raises:

ValueError – If no part has been added yet.

build() → z3fdb._internal.zarr.FdbZarrStore

Build the store from the registered parts.

Returns:

FdbZarrStore ready to pass to zarr.open_array().

Raises:

RuntimeError – If the view is misconfigured – no parts, a missing extension axis, incompatible part shapes, or parts that disagree about the grid. These originate as eckit::UserError in the C++ layer.