ak.ptp
======

Defined in `awkward.operations.ak_ptp <https://github.com/scikit-hep/awkward/blob/6549acea0193f5a82f58eedb62b9776ef3ec944b/src/awkward/operations/ak_ptp.py>`__ on `line 28 <https://github.com/scikit-hep/awkward/blob/6549acea0193f5a82f58eedb62b9776ef3ec944b/src/awkward/operations/ak_ptp.py#L28>`__.

.. py:function:: ak.ptp(array, axis=None, *, keepdims=False, mask_identity=True, highlevel=True, behavior=None, attrs=None)

   Returns the range of values over one or all levels of nesting.

   Many types are supported, including all Awkward Arrays and Records. The
   range of an empty list is None, unless ``mask_identity=False``, in which case
   it is 0. This operation is the same as NumPy's
   `ptp <https://docs.scipy.org/doc/numpy/reference/generated/numpy.ptp.html>`__
   if all lists at a given dimension have the same length and no None values,
   but it generalizes to cases where they do not.

   :param array: Array-like data (anything :py:obj:`ak.to_layout` recognizes).
   :param axis: If None, combine all values from the array into
                a single scalar result; if an int, group by that axis: ``0`` is the
                outermost, ``1`` is the first level of nested lists, etc., and
                negative ``axis`` counts from the innermost: ``-1`` is the innermost,
                ``-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 keepdims: If False, this reducer decreases the number of
                    dimensions by 1; if True, the reduced values are wrapped in a new
                    length-1 dimension so that the result of this operation may be
                    broadcasted with the original array.
   :type keepdims: bool
   :param mask_identity: If True, reducing over empty lists results in
                         None (an option type); otherwise, reducing over empty lists
                         results in the operation's identity of 0.
   :type mask_identity: bool

   :returns: The range of values in each group of elements from ``array``.

   .. rubric:: Examples

   For example, with

   >>> array = ak.Array([[0, 1, 2, 3],
   ...                   [          ],
   ...                   [4, 5      ]])

   The range of the innermost lists is

   >>> ak.ptp(array, axis=-1)
   <Array [3, None, 1] type='3 * ?int64'>

   because there are three lists, the first has a range of ``3``, the second is
   ``None`` because the list is empty, and the third has a range of ``1``. Similarly,

   >>> ak.ptp(array, axis=-1, mask_identity=False)
   <Array [3, 0, 1] type='3 * float64'>

   The second value is ``0`` because the list is empty.

   See :py:obj:`ak.sum` for a more complete description of nested list and missing
   value (None) handling in reducers.