Function _datatree_from_backend_datatree

xarray/backends/api.py:332–386

(
    backend_tree,
    filename_or_obj,
    engine,
    chunks,
    cache,
    overwrite_encoded_chunks,
    inline_array,
    chunked_array_type,
    from_array_kwargs,
    create_default_indexes,
    **extra_tokens,
)

def _datatree_from_backend_datatree(
    backend_tree,
    filename_or_obj,
    engine,
    chunks,
    cache,
    overwrite_encoded_chunks,
    inline_array,
    chunked_array_type,
    from_array_kwargs,
    create_default_indexes,
    **extra_tokens,
):
    if not isinstance(chunks, int | dict) and chunks not in {None, "auto"}:
        raise ValueError(
            f"chunks must be an int, dict, 'auto', or None. Instead found {chunks}."
        )

    _protect_datatree_variables_inplace(backend_tree, cache)
    if create_default_indexes:
        tree = backend_tree.map_over_datasets(_maybe_create_default_indexes)
    else:
        tree = backend_tree
    if chunks is not None:
        tree = DataTree.from_dict(
            {
                path: _chunk_ds(
                    node.dataset,
                    filename_or_obj,
                    engine,
                    chunks,
                    overwrite_encoded_chunks,
                    inline_array,
                    chunked_array_type,
                    from_array_kwargs,
                    node=path,
                    **extra_tokens,
                )
                for path, [node] in group_subtrees(tree)
            },
            name=tree.name,
        )

    if create_default_indexes or chunks is not None:
        for path, [node] in group_subtrees(backend_tree):
            tree[path].set_close(node._close)

    # Ensure source filename always stored in dataset object
    if "source" not in tree.encoding:
        path = getattr(filename_or_obj, "path", filename_or_obj)

        if isinstance(path, str | os.PathLike):
            tree.encoding["source"] = _normalize_path(path)

    return tree


def open_dataset(