# DataTree ## Creating a DataTree Methods of creating a `DataTree`. | [`DataTree`](../generated/xarray.DataTree.html.md#xarray.DataTree)([dataset, children, name]) | A tree-like hierarchical collection of xarray objects. | |-----------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------| | [`DataTree.from_dict`](../generated/xarray.DataTree.from_dict.html.md#xarray.DataTree.from_dict)([data, coords, name, nested]) | Create a datatree from a dictionary of data objects, organised by paths into the tree. | ## Tree Attributes Attributes relating to the recursive tree-like structure of a `DataTree`. | [`DataTree.parent`](../generated/xarray.DataTree.parent.html.md#xarray.DataTree.parent) | Parent of this node. | |---------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------| | [`DataTree.children`](../generated/xarray.DataTree.children.html.md#xarray.DataTree.children) | Child nodes of this node, stored under a mapping via their names. | | [`DataTree.name`](../generated/xarray.DataTree.name.html.md#xarray.DataTree.name) | The name of this node. | | [`DataTree.path`](../generated/xarray.DataTree.path.html.md#xarray.DataTree.path) | Return the file-like path from the root to this node. | | [`DataTree.root`](../generated/xarray.DataTree.root.html.md#xarray.DataTree.root) | Root node of the tree | | [`DataTree.is_root`](../generated/xarray.DataTree.is_root.html.md#xarray.DataTree.is_root) | Whether this node is the tree root. | | [`DataTree.is_leaf`](../generated/xarray.DataTree.is_leaf.html.md#xarray.DataTree.is_leaf) | Whether this node is a leaf node. | | [`DataTree.leaves`](../generated/xarray.DataTree.leaves.html.md#xarray.DataTree.leaves) | All leaf nodes. | | [`DataTree.level`](../generated/xarray.DataTree.level.html.md#xarray.DataTree.level) | Level of this node. | | [`DataTree.depth`](../generated/xarray.DataTree.depth.html.md#xarray.DataTree.depth) | Maximum level of this tree. | | [`DataTree.width`](../generated/xarray.DataTree.width.html.md#xarray.DataTree.width) | Number of nodes at this level in the tree. | | [`DataTree.subtree`](../generated/xarray.DataTree.subtree.html.md#xarray.DataTree.subtree) | Iterate over all nodes in this tree, including both self and all descendants. | | [`DataTree.subtree_with_keys`](../generated/xarray.DataTree.subtree_with_keys.html.md#xarray.DataTree.subtree_with_keys) | Iterate over relative paths and node pairs for all nodes in this tree. | | [`DataTree.descendants`](../generated/xarray.DataTree.descendants.html.md#xarray.DataTree.descendants) | Child nodes and all their child nodes. | | [`DataTree.siblings`](../generated/xarray.DataTree.siblings.html.md#xarray.DataTree.siblings) | Nodes with the same parent as this node. | | [`DataTree.lineage`](../generated/xarray.DataTree.lineage.html.md#xarray.DataTree.lineage) | All parent nodes and their parent nodes, starting with the closest. | | [`DataTree.parents`](../generated/xarray.DataTree.parents.html.md#xarray.DataTree.parents) | All parent nodes and their parent nodes, starting with the closest. | | [`DataTree.ancestors`](../generated/xarray.DataTree.ancestors.html.md#xarray.DataTree.ancestors) | All parent nodes and their parent nodes, starting with the most distant. | | [`DataTree.groups`](../generated/xarray.DataTree.groups.html.md#xarray.DataTree.groups) | Return all groups in the tree, given as a tuple of path-like strings. | | [`DataTree.xindexes`](../generated/xarray.DataTree.xindexes.html.md#xarray.DataTree.xindexes) | Mapping of xarray Index objects used for label based indexing. | ## Data Contents Interface to the data objects (optionally) stored inside a single `DataTree` node. This interface echoes that of `xarray.Dataset`. | [`DataTree.dims`](../generated/xarray.DataTree.dims.html.md#xarray.DataTree.dims) | Mapping from dimension names to lengths. | |------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------| | [`DataTree.sizes`](../generated/xarray.DataTree.sizes.html.md#xarray.DataTree.sizes) | Mapping from dimension names to lengths. | | [`DataTree.data_vars`](../generated/xarray.DataTree.data_vars.html.md#xarray.DataTree.data_vars) | Dictionary of DataArray objects corresponding to data variables | | [`DataTree.ds`](../generated/xarray.DataTree.ds.html.md#xarray.DataTree.ds) | An immutable Dataset-like view onto the data in this node. | | [`DataTree.coords`](../generated/xarray.DataTree.coords.html.md#xarray.DataTree.coords) | Dictionary of xarray.DataArray objects corresponding to coordinate variables | | [`DataTree.attrs`](../generated/xarray.DataTree.attrs.html.md#xarray.DataTree.attrs) | Dictionary of global attributes on this node object. | | [`DataTree.encoding`](../generated/xarray.DataTree.encoding.html.md#xarray.DataTree.encoding) | Dictionary of global encoding attributes on this node object. | | [`DataTree.indexes`](../generated/xarray.DataTree.indexes.html.md#xarray.DataTree.indexes) | Mapping of pandas.Index objects used for label based indexing. | | [`DataTree.nbytes`](../generated/xarray.DataTree.nbytes.html.md#xarray.DataTree.nbytes) | | | [`DataTree.dataset`](../generated/xarray.DataTree.dataset.html.md#xarray.DataTree.dataset) | An immutable Dataset-like view onto the data in this node. | | [`DataTree.to_dataset`](../generated/xarray.DataTree.to_dataset.html.md#xarray.DataTree.to_dataset)([inherit]) | Return the data in this node as a new xarray.Dataset object. | | [`DataTree.has_data`](../generated/xarray.DataTree.has_data.html.md#xarray.DataTree.has_data) | Whether or not there are any variables in this node. | | [`DataTree.has_attrs`](../generated/xarray.DataTree.has_attrs.html.md#xarray.DataTree.has_attrs) | Whether or not there are any metadata attributes in this node. | | [`DataTree.is_empty`](../generated/xarray.DataTree.is_empty.html.md#xarray.DataTree.is_empty) | False if node contains any data or attrs. | | [`DataTree.is_hollow`](../generated/xarray.DataTree.is_hollow.html.md#xarray.DataTree.is_hollow) | True if only leaf nodes contain data. | | [`DataTree.chunksizes`](../generated/xarray.DataTree.chunksizes.html.md#xarray.DataTree.chunksizes) | Mapping from group paths to a mapping of chunksizes. | ## Dictionary Interface `DataTree` objects also have a dict-like interface mapping keys to either `xarray.DataArray`s or to child `DataTree` nodes. | [`DataTree.__getitem__`](../generated/xarray.DataTree.__getitem__.html.md#xarray.DataTree.__getitem__)(key) | Access child nodes, variables, or coordinates stored anywhere in this tree. | |---------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------| | [`DataTree.__setitem__`](../generated/xarray.DataTree.__setitem__.html.md#xarray.DataTree.__setitem__)(key, value) | Add either a child node or an array to the tree, at any position. | | [`DataTree.__delitem__`](../generated/xarray.DataTree.__delitem__.html.md#xarray.DataTree.__delitem__)(key) | Remove a variable or child node from this datatree node. | | [`DataTree.update`](../generated/xarray.DataTree.update.html.md#xarray.DataTree.update)(other) | Update this node's children and / or variables. | | [`DataTree.get`](../generated/xarray.DataTree.get.html.md#xarray.DataTree.get)(key[, default]) | Access child nodes, variables, or coordinates stored in this node. | | [`DataTree.items`](../generated/xarray.DataTree.items.html.md#xarray.DataTree.items)() | | | [`DataTree.keys`](../generated/xarray.DataTree.keys.html.md#xarray.DataTree.keys)() | | | [`DataTree.values`](../generated/xarray.DataTree.values.html.md#xarray.DataTree.values)() | | ## Tree Manipulation For manipulating, traversing, navigating, or mapping over the tree structure. | [`DataTree.orphan`](../generated/xarray.DataTree.orphan.html.md#xarray.DataTree.orphan)() | Detach this node from its parent. | |---------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------| | [`DataTree.same_tree`](../generated/xarray.DataTree.same_tree.html.md#xarray.DataTree.same_tree)(other) | True if other node is in the same tree as this node. | | [`DataTree.relative_to`](../generated/xarray.DataTree.relative_to.html.md#xarray.DataTree.relative_to)(other) | Compute the relative path from this node to node other. | | [`DataTree.iter_lineage`](../generated/xarray.DataTree.iter_lineage.html.md#xarray.DataTree.iter_lineage)() | Iterate up the tree, starting from the current node. | | [`DataTree.find_common_ancestor`](../generated/xarray.DataTree.find_common_ancestor.html.md#xarray.DataTree.find_common_ancestor)(other) | Find the first common ancestor of two nodes in the same tree. | | [`DataTree.map_over_datasets`](../generated/xarray.DataTree.map_over_datasets.html.md#xarray.DataTree.map_over_datasets)(func, \*args[, kwargs]) | Apply a function to every dataset in this subtree, returning a new tree which stores the results. | | [`DataTree.pipe`](../generated/xarray.DataTree.pipe.html.md#xarray.DataTree.pipe)(func, \*args, \*\*kwargs) | Apply `func(self, *args, **kwargs)` | | [`DataTree.match`](../generated/xarray.DataTree.match.html.md#xarray.DataTree.match)(pattern) | Return nodes with paths matching pattern. | | [`DataTree.filter`](../generated/xarray.DataTree.filter.html.md#xarray.DataTree.filter)(filterfunc) | Filter nodes according to a specified condition. | | [`DataTree.filter_like`](../generated/xarray.DataTree.filter_like.html.md#xarray.DataTree.filter_like)(other) | Filter a datatree like another datatree. | ## Pathlib-like Interface `DataTree` objects deliberately echo some of the API of [`pathlib.PurePath`](https://docs.python.org/3/library/pathlib.html#pathlib.PurePath). | [`DataTree.name`](../generated/xarray.DataTree.name.html.md#xarray.DataTree.name) | The name of this node. | |----------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------| | [`DataTree.parent`](../generated/xarray.DataTree.parent.html.md#xarray.DataTree.parent) | Parent of this node. | | [`DataTree.parents`](../generated/xarray.DataTree.parents.html.md#xarray.DataTree.parents) | All parent nodes and their parent nodes, starting with the closest. | | [`DataTree.relative_to`](../generated/xarray.DataTree.relative_to.html.md#xarray.DataTree.relative_to)(other) | Compute the relative path from this node to node other. | ## DataTree Contents Manipulate the contents of all nodes in a `DataTree` simultaneously. | [`DataTree.copy`](../generated/xarray.DataTree.copy.html.md#xarray.DataTree.copy)(\*[, inherit, deep]) | Returns a copy of this subtree. | |------------------------------------------------------------------------------------------------------------|-----------------------------------| ## DataTree Node Contents Manipulate the contents of a single `DataTree` node. | [`DataTree.assign`](../generated/xarray.DataTree.assign.html.md#xarray.DataTree.assign)([items]) | Assign new data variables or child nodes to a DataTree, returning a new object with all the original items in addition to the new ones. | |----------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------| | [`DataTree.drop_nodes`](../generated/xarray.DataTree.drop_nodes.html.md#xarray.DataTree.drop_nodes)(names, \*[, errors]) | Drop child nodes from this node. | ## DataTree Operations Apply operations over multiple `DataTree` objects. | [`map_over_datasets`](../generated/xarray.map_over_datasets.html.md#xarray.map_over_datasets)(func, \*args[, kwargs]) | Applies a function to every dataset in one or more DataTree objects with the same structure (ie.., that are isomorphic), returning new trees which store the results. | |-----------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | [`group_subtrees`](../generated/xarray.group_subtrees.html.md#xarray.group_subtrees)(\*trees) | Iterate over subtrees grouped by relative paths in breadth-first order. | ## Comparisons Compare one `DataTree` object to another. | [`DataTree.isomorphic`](../generated/xarray.DataTree.isomorphic.html.md#xarray.DataTree.isomorphic)(other) | Two DataTrees are considered isomorphic if the set of paths to their descendent nodes are the same. | |----------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | [`DataTree.equals`](../generated/xarray.DataTree.equals.html.md#xarray.DataTree.equals)(other) | Two DataTrees are equal if they have isomorphic node structures, with matching node names, and if they have matching variables and coordinates, all of which are equal. | | [`DataTree.identical`](../generated/xarray.DataTree.identical.html.md#xarray.DataTree.identical)(other) | Like equals, but also checks attributes on all datasets, variables and coordinates, and requires that any inherited coordinates at the tree root are also inherited on the other tree. | ## Indexing Index into all nodes in the subtree simultaneously. | [`DataTree.isel`](../generated/xarray.DataTree.isel.html.md#xarray.DataTree.isel)([indexers, drop, missing_dims]) | Returns a new data tree with each array indexed along the specified dimension(s). | |------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------| | [`DataTree.sel`](../generated/xarray.DataTree.sel.html.md#xarray.DataTree.sel)([indexers, method, tolerance, drop]) | Returns a new data tree with each array indexed by tick labels along the specified dimension(s). | ## Aggregation Aggregate data in all nodes in the subtree simultaneously. | [`DataTree.all`](../generated/xarray.DataTree.all.html.md#xarray.DataTree.all)([dim, keep_attrs]) | Reduce this DataTree's data by applying `all` along some dimension(s). | |----------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------| | [`DataTree.any`](../generated/xarray.DataTree.any.html.md#xarray.DataTree.any)([dim, keep_attrs]) | Reduce this DataTree's data by applying `any` along some dimension(s). | | [`DataTree.max`](../generated/xarray.DataTree.max.html.md#xarray.DataTree.max)([dim, skipna, keep_attrs]) | Reduce this DataTree's data by applying `max` (i.e., maximum) along some dimension(s). | | [`DataTree.min`](../generated/xarray.DataTree.min.html.md#xarray.DataTree.min)([dim, skipna, keep_attrs]) | Reduce this DataTree's data by applying `min` (i.e., minimum) along some dimension(s). | | [`DataTree.mean`](../generated/xarray.DataTree.mean.html.md#xarray.DataTree.mean)([dim, skipna, keep_attrs]) | Reduce this DataTree's data by applying `mean` along some dimension(s). | | [`DataTree.median`](../generated/xarray.DataTree.median.html.md#xarray.DataTree.median)([dim, skipna, keep_attrs]) | Reduce this DataTree's data by applying `median` along some dimension(s). | | [`DataTree.prod`](../generated/xarray.DataTree.prod.html.md#xarray.DataTree.prod)([dim, skipna, min_count, ...]) | Reduce this DataTree's data by applying `prod` (i.e., product) along some dimension(s). | | [`DataTree.sum`](../generated/xarray.DataTree.sum.html.md#xarray.DataTree.sum)([dim, skipna, min_count, ...]) | Reduce this DataTree's data by applying `sum` along some dimension(s). | | [`DataTree.std`](../generated/xarray.DataTree.std.html.md#xarray.DataTree.std)([dim, skipna, ddof, keep_attrs]) | Reduce this DataTree's data by applying `std` (i.e., standard deviation) along some dimension(s). | | [`DataTree.var`](../generated/xarray.DataTree.var.html.md#xarray.DataTree.var)([dim, skipna, ddof, keep_attrs]) | Reduce this DataTree's data by applying `var` (i.e., variance) along some dimension(s). | | [`DataTree.cumsum`](../generated/xarray.DataTree.cumsum.html.md#xarray.DataTree.cumsum)([dim, skipna, keep_attrs]) | Reduce this DataTree's data by applying `cumsum` (i.e., cumulative sum) along some dimension(s). | | [`DataTree.cumprod`](../generated/xarray.DataTree.cumprod.html.md#xarray.DataTree.cumprod)([dim, skipna, keep_attrs]) | Reduce this DataTree's data by applying `cumprod` (i.e., cumulative product) along some dimension(s). | ## ndarray methods Methods copied from [`numpy.ndarray`](https://numpy.org/doc/stable/reference/generated/numpy.ndarray.html#numpy.ndarray) objects, here applying to the data in all nodes in the subtree. | [`DataTree.argsort`](../generated/xarray.DataTree.argsort.html.md#xarray.DataTree.argsort)([axis, kind, order, ...]) | Returns the indices that would sort this array. | |-----------------------------------------------------------------------------------------------------------------------|---------------------------------------------------| | [`DataTree.conj`](../generated/xarray.DataTree.conj.html.md#xarray.DataTree.conj)() | Complex-conjugate all elements. | | [`DataTree.conjugate`](../generated/xarray.DataTree.conjugate.html.md#xarray.DataTree.conjugate)(\*args, \*\*kwargs) | a.conj() | | [`DataTree.round`](../generated/xarray.DataTree.round.html.md#xarray.DataTree.round)(\*args, \*\*kwargs) | |