xarray.Dataset.set_index

Dataset.set_index(indexes=None, append=False, inplace=None, **indexes_kwargs)

Set Dataset (multi-)indexes using one or more existing coordinates or variables.

Parameters
  • indexes ({dim: index, ..}) – Mapping from names matching dimensions and values given by (lists of) the names of existing coordinates or variables to set as new (multi-)index.

  • append (bool, optional) – If True, append the supplied index(es) to the existing index(es). Otherwise replace the existing index(es) (default).

  • **indexes_kwargs (optional) – The keyword arguments form of indexes. One of indexes or indexes_kwargs must be provided.

Returns

obj – Another dataset, with this dataset’s data but replaced coordinates.

Return type

Dataset

Examples

>>> arr = xr.DataArray(data=np.ones((2, 3)),
...                    dims=['x', 'y'],
...                    coords={'x':
...                        range(2), 'y':
...                        range(3), 'a': ('x', [3, 4])
...                    })
>>> ds = xr.Dataset({'v': arr})
>>> ds
<xarray.Dataset>
Dimensions:  (x: 2, y: 3)
Coordinates:
  * x        (x) int64 0 1
  * y        (y) int64 0 1 2
    a        (x) int64 3 4
Data variables:
    v        (x, y) float64 1.0 1.0 1.0 1.0 1.0 1.0
>>> ds.set_index(x='a')
<xarray.Dataset>
Dimensions:  (x: 2, y: 3)
Coordinates:
  * x        (x) int64 3 4
  * y        (y) int64 0 1 2
Data variables:
    v        (x, y) float64 1.0 1.0 1.0 1.0 1.0 1.0