Defined in awkward.operations.structure on line 2724.

ak.fill_none(array, value, axis=- 1, highlevel=True, behavior=None)
  • array – Data in which to replace None with a given value.

  • value – Data with which to replace None.

  • axis (None or int) – 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.

  • highlevel (bool) – If True, return an ak.Array; otherwise, return a low-level ak.layout.Content subclass.

  • behavior (None or dict) – Custom ak.behavior for the output array, if high-level.

Replaces missing values (None) with a given value.

For example, in the following array,

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

The None values could be replaced with 0 by

>>> 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.

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

The list content now has a union type:

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

The values could be floating-point numbers or strings.