Source code for xcube.core.mldataset.combined

# Copyright (c) 2018-2024 by xcube team and contributors
# Permissions are hereby granted under the terms of the MIT License:

from typing import Sequence, Any, Dict, Callable, Optional

import xarray as xr

from .abc import MultiLevelDataset
from .lazy import LazyMultiLevelDataset

[docs] class CombinedMultiLevelDataset(LazyMultiLevelDataset): """A multi-level dataset that is a combination of other multi-level datasets. Args: ml_datasets: The multi-level datasets to be combined. At least two must be provided. ds_id: Optional dataset identifier. combiner_function: An optional function used to combine the datasets, for example ``xarray.merge``. If given, it receives a list of datasets (``xarray.Dataset`` instances) and *combiner_params* as keyword arguments. If not given or ``None`` is passed, a copy of the first dataset is made, which is then subsequently updated by the remaining datasets using ``xarray.Dataset.update()``. combiner_params: Parameters to the *combiner_function* passed as keyword arguments. """ def __init__( self, ml_datasets: Sequence[MultiLevelDataset], ds_id: Optional[str] = None, combiner_function: Optional[Callable] = None, combiner_params: Optional[Dict[str, Any]] = None, ): if not ml_datasets or len(ml_datasets) < 2: raise ValueError("ml_datasets must have at least two elements") super().__init__(ds_id=ds_id, parameters=combiner_params) self._ml_datasets = ml_datasets self._combiner_function = combiner_function def _get_num_levels_lazily(self) -> int: return self._ml_datasets[0].num_levels def _get_dataset_lazily( self, index: int, combiner_params: Dict[str, Any] ) -> xr.Dataset: datasets = [ml_dataset.get_dataset(index) for ml_dataset in self._ml_datasets] if self._combiner_function is None: combined_dataset = datasets[0].copy() for dataset in datasets[1:]: combined_dataset.update(dataset) return combined_dataset else: return self._combiner_function(datasets, **combiner_params)
[docs] def close(self): for ml_dataset in self._ml_datasets: ml_dataset.close()