pyflink.dataframe.dataframe.DataFrame.fill_null

DataFrame.fill_null(value: Any, subset: List[str] | None = None) → DataFrame

Replace null values with a given value.

Does NOT replace NaN — use fill_nan() for that.

Parameters:

• value – The value to replace nulls with.

• subset – Column names to fill. If None, fills all columns.

Returns:

A new DataFrame with null values replaced.

Example::

>>> df.fill_null(0)                  # fill all columns
>>> df.fill_null(0, subset=["a"])     # fill only column "a"