Function _block_info_recursion

numpy/core/shape_base.py:620–670

Returns the shape of the final array, along with a list of slices and a list of arrays that can be used for assignment inside the new array Parameters ---------- arrays : nested list of arrays The arrays to check max_depth : list of int The number of nes

(arrays, max_depth, result_ndim, depth=0)

def _block_info_recursion(arrays, max_depth, result_ndim, depth=0):
    """
    Returns the shape of the final array, along with a list
    of slices and a list of arrays that can be used for assignment inside the
    new array

    Parameters
    ----------
    arrays : nested list of arrays
        The arrays to check
    max_depth : list of int
        The number of nested lists
    result_ndim : int
        The number of dimensions in thefinal array.

    Returns
    -------
    shape : tuple of int
        The shape that the final array will take on.
    slices: list of tuple of slices
        The slices into the full array required for assignment. These are
        required to be prepended with ``(Ellipsis, )`` to obtain to correct
        final index.
    arrays: list of ndarray
        The data to assign to each slice of the full array

    """
    if depth < max_depth:
        shapes, slices, arrays = zip(
            *[_block_info_recursion(arr, max_depth, result_ndim, depth+1)
              for arr in arrays])

        axis = result_ndim - max_depth + depth
        shape, slice_prefixes = _concatenate_shapes(shapes, axis)

        # Prepend the slice prefix and flatten the slices
        slices = [slice_prefix + the_slice
                  for slice_prefix, inner_slices in zip(slice_prefixes, slices)
                  for the_slice in inner_slices]

        # Flatten the array list
        arrays = functools.reduce(operator.add, arrays)

        return shape, slices, arrays
    else:
        # We've 'bottomed out' - arrays is either a scalar or an array
        # type(arrays) is not list
        # Return the slice and the array inside a list to be consistent with
        # the recursive case.
        arr = _atleast_nd(arrays, result_ndim)
        return arr.shape, [()], [arr]


def _block(arrays, max_depth, result_ndim, depth=0):