Method fillna

xarray/core/dataset.py:6436–6514

Fill missing values in this object. This operation follows the normal broadcasting and alignment rules that xarray uses for binary arithmetic, except the result is aligned to this object (``join='left'``) instead of aligned to the intersection of index coordinates (`

(self, value: Any)

        return self.isel({dim: mask})

    def fillna(self, value: Any) -> Self:
        """Fill missing values in this object.

        This operation follows the normal broadcasting and alignment rules that
        xarray uses for binary arithmetic, except the result is aligned to this
        object (``join='left'``) instead of aligned to the intersection of
        index coordinates (``join='inner'``).

        Parameters
        ----------
        value : scalar, ndarray, DataArray, dict or Dataset
            Used to fill all matching missing values in this dataset's data
            variables. Scalars, ndarrays or DataArrays arguments are used to
            fill all data with aligned coordinates (for DataArrays).
            Dictionaries or datasets match data variables and then align
            coordinates if necessary.

        Returns
        -------
        Dataset

        Examples
        --------
        >>> ds = xr.Dataset(
        ...     {
        ...         "A": ("x", [np.nan, 2, np.nan, 0]),
        ...         "B": ("x", [3, 4, np.nan, 1]),
        ...         "C": ("x", [np.nan, np.nan, np.nan, 5]),
        ...         "D": ("x", [np.nan, 3, np.nan, 4]),
        ...     },
        ...     coords={"x": [0, 1, 2, 3]},
        ... )
        >>> ds
        <xarray.Dataset> Size: 160B
        Dimensions:  (x: 4)
        Coordinates:
          * x        (x) int64 32B 0 1 2 3
        Data variables:
            A        (x) float64 32B nan 2.0 nan 0.0
            B        (x) float64 32B 3.0 4.0 nan 1.0
            C        (x) float64 32B nan nan nan 5.0
            D        (x) float64 32B nan 3.0 nan 4.0

        Replace all `NaN` values with 0s.

        >>> ds.fillna(0)
        <xarray.Dataset> Size: 160B
        Dimensions:  (x: 4)
        Coordinates:
          * x        (x) int64 32B 0 1 2 3
        Data variables:
            A        (x) float64 32B 0.0 2.0 0.0 0.0
            B        (x) float64 32B 3.0 4.0 0.0 1.0
            C        (x) float64 32B 0.0 0.0 0.0 5.0
            D        (x) float64 32B 0.0 3.0 0.0 4.0

        Replace all `NaN` elements in column ‘A’, ‘B’, ‘C’, and ‘D’, with 0, 1, 2, and 3 respectively.