ak.to_regular
-------------

.. py:module: ak.to_regular

Defined in `awkward.operations.ak_to_regular <https://github.com/scikit-hep/awkward/blob/b0c462c88eff0e2bb911987665aa69f9e2fbf145/src/awkward/operations/ak_to_regular.py>`__ on `line 18 <https://github.com/scikit-hep/awkward/blob/b0c462c88eff0e2bb911987665aa69f9e2fbf145/src/awkward/operations/ak_to_regular.py#L18>`__.

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


    :param array: Array-like data (anything :py:obj:`ak.to_layout` recognizes).
    :param axis: 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 None, convert all
             variable dimensions into regular ones or raise a ValueError if that
             is not possible.
    :type axis: int or None
    :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

Converts a variable-length axis into a regular one, if possible.

.. code-block:: python


    >>> irregular = ak.from_iter(np.arange(2*3*5).reshape(2, 3, 5))
    >>> irregular.type.show()
    2 * var * var * int64
    >>> ak.to_regular(irregular).type.show()
    2 * 3 * var * int64
    >>> ak.to_regular(irregular, axis=2).type.show()
    2 * var * 5 * int64
    >>> ak.to_regular(irregular, axis=-1).type.show()
    2 * var * 5 * int64

But truly irregular data cannot be converted.

.. code-block:: python


    >>> ak.to_regular(ak.Array([[1, 2, 3], [], [4, 5]]))
    ValueError: while calling
        ak.to_regular(
            array = <Array [[1, 2, 3], [], [4, 5]] type='3 * var * int64'>
            axis = 1
            highlevel = True
            behavior = None
        )
    Error details: cannot convert to RegularArray because subarray lengths are not regular

See also :py:obj:`ak.from_regular`.