ak.fill_none
------------

.. py:module: ak.fill_none

Defined in `awkward.operations.ak_fill_none <https://github.com/scikit-hep/awkward/blob/3fb10da4090fd281f143dcc9decf48e914342379/src/awkward/operations/ak_fill_none.py>`__ on `line 22 <https://github.com/scikit-hep/awkward/blob/3fb10da4090fd281f143dcc9decf48e914342379/src/awkward/operations/ak_fill_none.py#L22>`__.

.. py:function:: ak.fill_none(array, value, axis=-1, *, highlevel=True, behavior=None, attrs=None)


    :param array: Array-like data (anything :py:obj:`ak.to_layout` recognizes).
    :param value: Data with which to replace None.
    :param axis: If None, replace all None values in the
             array with the given value.
             If an int, the dimension at which this operation is applied.
             The outermost dimension is ``0``, followed by ``1``, etc., and negative
             values count backward from the innermost: ``-1`` is the innermost
             dimension, ``-2`` is the next level up, etc.
             If a str, it is interpreted as the name of the axis which maps to
             an int if named axes are present.
             Named axes are attached to an array using :py:obj:`ak.with_named_axis` and
             removed with :py:obj:`ak.without_named_axis`; also see the
             `Named axes user guide <../../user-guide/how-to-array-properties-named-axis.html>`__.
    :type axis: None or int or str
    :param highlevel: If True, return an :py:obj:`ak.Array`; otherwise, return
                  a low-level :py:obj:`ak.contents.Content` subclass.
    :type highlevel: bool
    :param behavior: Custom :py:obj:`ak.behavior` for the output array, if
                 high-level.
    :type behavior: None or dict
    :param attrs: Custom attributes for the output array, if
              high-level.
    :type attrs: None or dict

Replaces missing values (None) with a given ``value``.

For example, in the following

.. code-block:: python


    >>> array = ak.Array([[1.1, None, 2.2], [], [None, 3.3, 4.4]])

The None values could be replaced with ``0`` by

.. code-block:: python


    >>> ak.fill_none(array, 0)
    <Array [[1.1, 0, 2.2], [], [0, 3.3, 4.4]] type='3 * var * float64'>

The replacement value doesn't strictly need the same type as the
surrounding data. For example, the None values could also be replaced
by a string.

.. code-block:: python


    >>> ak.fill_none(array, "hi")
    <Array [[1.1, 'hi', 2.2], [], ['hi', ...]] type='3 * var * union[float64, s...'>

The list content now has a union type:

.. code-block:: python


    >>> ak.fill_none(array, "hi").type.show()
    3 * var * union[
        float64,
        string
    ]

The values could be floating-point numbers or strings.