# xarray.IndexVariable ### *class* xarray.IndexVariable(dims, data, attrs=None, encoding=None, fastpath=False)[[source]](https://github.com/pydata/xarray/blob/main/xarray/core/variable.py#L2989-L3365) Wrapper for accommodating a pandas.Index in an xarray.Variable. IndexVariable preserve loaded values in the form of a pandas.Index instead of a NumPy array. Hence, their values are immutable and must always be one- dimensional. They also have a name property, which is the name of their sole dimension unless another name is given. #### \_\_init_\_(dims, data, attrs=None, encoding=None, fastpath=False)[[source]](https://github.com/pydata/xarray/blob/main/xarray/core/variable.py#L3097-L3111) * **Parameters:** * **dims** ([`str`](https://docs.python.org/3/builtins/stdtypes.html#str) or [sequence](https://docs.python.org/3/glossary.html#term-sequence) of [`str`](https://docs.python.org/3/builtins/stdtypes.html#str)) – Name(s) of the the data dimension(s). Must be either a string (only for 1D data) or a sequence of strings with length equal to the number of dimensions. * **data** ([array_like](https://numpy.org/doc/stable/glossary.html#term-array_like)) – Data array which supports numpy-like data access. * **attrs** ([dict-like](https://docs.python.org/3/glossary.html#term-mapping) or [`None`](https://docs.python.org/3/builtins/constants.html#None), *optional*) – Attributes to assign to the new variable. If None (default), an empty attribute dictionary is initialized. (see FAQ, [What is your approach to metadata?](../get-help/faq.html.md#approach-to-metadata)) * **encoding** ([dict-like](https://docs.python.org/3/glossary.html#term-mapping) or [`None`](https://docs.python.org/3/builtins/constants.html#None), *optional*) – Dictionary specifying how to encode this array’s data into a serialized format like netCDF4. Currently used keys (for netCDF) include ‘_FillValue’, ‘scale_factor’, ‘add_offset’ and ‘dtype’. Well-behaved code to serialize a Variable should ignore unrecognized encoding items. ### Methods | [`__init__`](#xarray.IndexVariable.__init__)(dims, data[, attrs, encoding, fastpath]) | | |-----------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------| | [`all`](xarray.IndexVariable.all.html.md#xarray.IndexVariable.all)([dim]) | Reduce this NamedArray's data by applying `all` along some dimension(s). | | [`any`](xarray.IndexVariable.any.html.md#xarray.IndexVariable.any)([dim]) | Reduce this NamedArray's data by applying `any` along some dimension(s). | | [`argmax`](xarray.IndexVariable.argmax.html.md#xarray.IndexVariable.argmax)([dim, axis, keep_attrs, skipna]) | Index or indices of the maximum of the Variable over one or more dimensions. | | [`argmin`](xarray.IndexVariable.argmin.html.md#xarray.IndexVariable.argmin)([dim, axis, keep_attrs, skipna]) | Index or indices of the minimum of the Variable over one or more dimensions. | | [`argsort`](xarray.IndexVariable.argsort.html.md#xarray.IndexVariable.argsort)([axis, kind, order, stable, descending]) | Returns the indices that would sort this array. | | `as_numpy`() | Coerces wrapped data into a numpy array, returning a Variable. | | [`astype`](xarray.IndexVariable.astype.html.md#xarray.IndexVariable.astype)(dtype, \*[, order, casting, subok, ...]) | Copy of the Variable object, with data cast to a specified type. | | [`broadcast_equals`](xarray.IndexVariable.broadcast_equals.html.md#xarray.IndexVariable.broadcast_equals)(other[, equiv]) | True if two Variables have the values after being broadcast against each other; otherwise False. | | `broadcast_to`([dim]) | Broadcast the NamedArray to a new shape. | | [`chunk`](xarray.IndexVariable.chunk.html.md#xarray.IndexVariable.chunk)([chunks, name, lock, inline_array, ...]) | Coerce this array's data into a dask array with the given chunks. | | [`clip`](xarray.IndexVariable.clip.html.md#xarray.IndexVariable.clip)([min, max]) | Return an array whose values are limited to `[min, max]`. | | [`coarsen`](xarray.IndexVariable.coarsen.html.md#xarray.IndexVariable.coarsen)(windows, func[, boundary, side, ...]) | Apply reduction function. | | `coarsen_reshape`(windows, boundary, side) | Construct a reshaped-array for coarsen | | [`compute`](xarray.IndexVariable.compute.html.md#xarray.IndexVariable.compute)(\*\*kwargs) | Trigger loading data into memory and return a new variable. | | [`concat`](xarray.IndexVariable.concat.html.md#xarray.IndexVariable.concat)(variables[, dim, positions, ...]) | Specialized version of Variable.concat for IndexVariable objects. | | [`conj`](xarray.IndexVariable.conj.html.md#xarray.IndexVariable.conj)() | Complex-conjugate all elements. | | [`conjugate`](xarray.IndexVariable.conjugate.html.md#xarray.IndexVariable.conjugate)(\*args, \*\*kwargs) | a.conj() | | [`copy`](xarray.IndexVariable.copy.html.md#xarray.IndexVariable.copy)([deep, data]) | Returns a copy of this object. | | [`count`](xarray.IndexVariable.count.html.md#xarray.IndexVariable.count)([dim]) | Reduce this NamedArray's data by applying `count` along some dimension(s). | | [`cumprod`](xarray.IndexVariable.cumprod.html.md#xarray.IndexVariable.cumprod)([dim, skipna]) | Reduce this NamedArray's data by applying `cumprod` (i.e., cumulative product) along some dimension(s). | | [`cumsum`](xarray.IndexVariable.cumsum.html.md#xarray.IndexVariable.cumsum)([dim, skipna]) | Reduce this NamedArray's data by applying `cumsum` (i.e., cumulative sum) along some dimension(s). | | `drop_encoding`() | Return a new Variable without encoding. | | [`equals`](xarray.IndexVariable.equals.html.md#xarray.IndexVariable.equals)(other[, equiv]) | True if two Variables have the same dimensions and values; otherwise False. | | `expand_dims`([dim]) | Expand the dimensions of the NamedArray. | | [`fillna`](xarray.IndexVariable.fillna.html.md#xarray.IndexVariable.fillna)(value) | | | [`get_axis_num`](xarray.IndexVariable.get_axis_num.html.md#xarray.IndexVariable.get_axis_num)(dim) | Return axis number(s) corresponding to dimension(s) in this array. | | [`get_level_variable`](xarray.IndexVariable.get_level_variable.html.md#xarray.IndexVariable.get_level_variable)(level) | Return a new IndexVariable from a given MultiIndex level. | | [`identical`](xarray.IndexVariable.identical.html.md#xarray.IndexVariable.identical)(other[, equiv]) | Like equals, but also checks attributes. | | [`isel`](xarray.IndexVariable.isel.html.md#xarray.IndexVariable.isel)([indexers, missing_dims]) | Return a new array indexed along the specified dimension(s). | | [`isnull`](xarray.IndexVariable.isnull.html.md#xarray.IndexVariable.isnull)([keep_attrs]) | Test each value in the array for whether it is a missing value. | | [`item`](xarray.IndexVariable.item.html.md#xarray.IndexVariable.item)(\*args) | Copy an element of an array to a standard Python scalar and return it. | | [`load`](xarray.IndexVariable.load.html.md#xarray.IndexVariable.load)() | Trigger loading data into memory and return this variable. | | `load_async`() | Trigger and await asynchronous loading of data into memory and return this variable. | | [`max`](xarray.IndexVariable.max.html.md#xarray.IndexVariable.max)([dim, skipna]) | Reduce this NamedArray's data by applying `max` (i.e., maximum) along some dimension(s). | | [`mean`](xarray.IndexVariable.mean.html.md#xarray.IndexVariable.mean)([dim, skipna]) | Reduce this NamedArray's data by applying `mean` along some dimension(s). | | [`median`](xarray.IndexVariable.median.html.md#xarray.IndexVariable.median)([dim, skipna]) | Reduce this NamedArray's data by applying `median` along some dimension(s). | | [`min`](xarray.IndexVariable.min.html.md#xarray.IndexVariable.min)([dim, skipna]) | Reduce this NamedArray's data by applying `min` (i.e., minimum) along some dimension(s). | | [`no_conflicts`](xarray.IndexVariable.no_conflicts.html.md#xarray.IndexVariable.no_conflicts)(other[, equiv]) | True if the intersection of two Variable's non-null data is equal; otherwise false. | | [`notnull`](xarray.IndexVariable.notnull.html.md#xarray.IndexVariable.notnull)([keep_attrs]) | Test each value in the array for whether it is not a missing value. | | [`pad`](xarray.IndexVariable.pad.html.md#xarray.IndexVariable.pad)([pad_width, mode, stat_length, ...]) | Return a new Variable with padded data. | | `permute_dims`(\*dim[, missing_dims]) | Return a new object with transposed dimensions. | | [`prod`](xarray.IndexVariable.prod.html.md#xarray.IndexVariable.prod)([dim, skipna, min_count]) | Reduce this NamedArray's data by applying `prod` (i.e., product) along some dimension(s). | | [`quantile`](xarray.IndexVariable.quantile.html.md#xarray.IndexVariable.quantile)(q[, dim, method, keep_attrs, ...]) | Compute the qth quantile of the data along the specified dimension. | | [`rank`](xarray.IndexVariable.rank.html.md#xarray.IndexVariable.rank)(dim[, pct]) | Ranks the data. | | [`reduce`](xarray.IndexVariable.reduce.html.md#xarray.IndexVariable.reduce)(func[, dim, axis, keep_attrs, keepdims]) | Reduce this array by applying func along some dimension(s). | | `reset_encoding`() | | | [`roll`](xarray.IndexVariable.roll.html.md#xarray.IndexVariable.roll)([shifts]) | Return a new Variable with rolled data. | | [`rolling_window`](xarray.IndexVariable.rolling_window.html.md#xarray.IndexVariable.rolling_window)(dim, window, window_dim, \*[, ...]) | Make a rolling_window along dim and add a new_dim to the last place. | | [`round`](xarray.IndexVariable.round.html.md#xarray.IndexVariable.round)(\*args, \*\*kwargs) | | | [`searchsorted`](xarray.IndexVariable.searchsorted.html.md#xarray.IndexVariable.searchsorted)(v[, side, sorter]) | Find indices where elements of v should be inserted in a to maintain order. | | [`set_dims`](xarray.IndexVariable.set_dims.html.md#xarray.IndexVariable.set_dims)(dim[, shape]) | Return a new variable with given set of dimensions. | | [`shift`](xarray.IndexVariable.shift.html.md#xarray.IndexVariable.shift)([shifts, fill_value]) | Return a new Variable with shifted data. | | [`squeeze`](xarray.IndexVariable.squeeze.html.md#xarray.IndexVariable.squeeze)([dim]) | Return a new object with squeezed data. | | [`stack`](xarray.IndexVariable.stack.html.md#xarray.IndexVariable.stack)([dim]) | Stack any number of existing dim into a single new dimension. | | [`std`](xarray.IndexVariable.std.html.md#xarray.IndexVariable.std)([dim, skipna, ddof]) | Reduce this NamedArray's data by applying `std` (i.e., standard deviation) along some dimension(s). | | [`sum`](xarray.IndexVariable.sum.html.md#xarray.IndexVariable.sum)([dim, skipna, min_count]) | Reduce this NamedArray's data by applying `sum` along some dimension(s). | | [`to_base_variable`](xarray.IndexVariable.to_base_variable.html.md#xarray.IndexVariable.to_base_variable)() | Return this variable as a base xarray.Variable | | [`to_dict`](xarray.IndexVariable.to_dict.html.md#xarray.IndexVariable.to_dict)([data, encoding]) | Dictionary representation of variable. | | [`to_index`](xarray.IndexVariable.to_index.html.md#xarray.IndexVariable.to_index)() | Convert this variable to a pandas.Index | | [`to_index_variable`](xarray.IndexVariable.to_index_variable.html.md#xarray.IndexVariable.to_index_variable)() | Return this variable as an xarray.IndexVariable | | `to_numpy`() | Coerces wrapped data to numpy and returns a numpy.ndarray | | [`transpose`](xarray.IndexVariable.transpose.html.md#xarray.IndexVariable.transpose)(\*dim[, missing_dims]) | Return a new Variable object with transposed dimensions. | | [`unstack`](xarray.IndexVariable.unstack.html.md#xarray.IndexVariable.unstack)([dim]) | Unstack an existing dimension into multiple new dimensions. | | [`var`](xarray.IndexVariable.var.html.md#xarray.IndexVariable.var)([dim, skipna, ddof]) | Reduce this NamedArray's data by applying `var` (i.e., variance) along some dimension(s). | | [`where`](xarray.IndexVariable.where.html.md#xarray.IndexVariable.where)(cond[, other]) | | ### Attributes | [`T`](xarray.IndexVariable.T.html.md#xarray.IndexVariable.T) | Return a new object with transposed dimensions. | |-----------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------| | [`attrs`](xarray.IndexVariable.attrs.html.md#xarray.IndexVariable.attrs) | Dictionary of local attributes on this NamedArray. | | [`chunks`](xarray.IndexVariable.chunks.html.md#xarray.IndexVariable.chunks) | Tuple of block lengths for this NamedArray's data, in order of dimensions, or None if the underlying data is not a dask array. | | `chunksizes` | Mapping from dimension names to block lengths for this NamedArray's data. | | [`data`](xarray.IndexVariable.data.html.md#xarray.IndexVariable.data) | The Variable's data as an array. | | [`dims`](xarray.IndexVariable.dims.html.md#xarray.IndexVariable.dims) | Tuple of dimension names with which this NamedArray is associated. | | [`dtype`](xarray.IndexVariable.dtype.html.md#xarray.IndexVariable.dtype) | Data-type of the array’s elements. | | [`encoding`](xarray.IndexVariable.encoding.html.md#xarray.IndexVariable.encoding) | Dictionary of encodings on this variable. | | [`imag`](xarray.IndexVariable.imag.html.md#xarray.IndexVariable.imag) | The imaginary part of the variable. | | [`level_names`](xarray.IndexVariable.level_names.html.md#xarray.IndexVariable.level_names) | Return MultiIndex level names or None if this IndexVariable has no MultiIndex. | | [`name`](xarray.IndexVariable.name.html.md#xarray.IndexVariable.name) | | | [`nbytes`](xarray.IndexVariable.nbytes.html.md#xarray.IndexVariable.nbytes) | Total bytes consumed by the elements of the data array. | | [`ndim`](xarray.IndexVariable.ndim.html.md#xarray.IndexVariable.ndim) | Number of array dimensions. | | [`real`](xarray.IndexVariable.real.html.md#xarray.IndexVariable.real) | The real part of the variable. | | [`shape`](xarray.IndexVariable.shape.html.md#xarray.IndexVariable.shape) | Get the shape of the array. | | [`size`](xarray.IndexVariable.size.html.md#xarray.IndexVariable.size) | Number of elements in the array. | | [`sizes`](xarray.IndexVariable.sizes.html.md#xarray.IndexVariable.sizes) | Ordered mapping from dimension names to lengths. | | [`values`](xarray.IndexVariable.values.html.md#xarray.IndexVariable.values) | The variable's data as a numpy.ndarray |