# xarray.DataArray.stack

`DataArray.``stack`(dimensions: Mapping[Hashable, Sequence[Hashable]] = None, **dimensions_kwargs) → xarray.core.dataarray.DataArray

  Stack any number of existing dimensions into a single new dimension.

  New dimensions will be added at the end, and the corresponding coordinate variables will be combined into a MultiIndex.

  Parameters:

  - dimensions (Mapping of the form new_name=(dim1, dim2, ..)) – Names of new dimensions, and the existing dimensions that they replace.
  - **dimensions_kwargs – The keyword arguments form of `dimensions`. One of dimensions or dimensions_kwargs must be provided.

  Returns: | stacked – DataArray with stacked data.
  Return type: | DataArray

  Examples

      >>> arr = DataArray(np.arange(6).reshape(2, 3),
      ...                 coords=[('x', ['a', 'b']), ('y', [0, 1, 2])])
      >>> arr
      <xarray.DataArray (x: 2, y: 3)>
      array([[0, 1, 2],
             [3, 4, 5]])
      Coordinates:
        * x        (x) |S1 'a' 'b'
        * y        (y) int64 0 1 2
      >>> stacked = arr.stack(z=('x', 'y'))
      >>> stacked.indexes['z']
      MultiIndex(levels=[['a', 'b'], [0, 1, 2]],
                 codes=[[0, 0, 0, 1, 1, 1], [0, 1, 2, 0, 1, 2]],
                 names=['x', 'y'])

  See also

  `DataArray.unstack()`