There is currently no kernel available to directly do this, but there is an
existing JIRA with a feature request for this:
https://issues.apache.org/jira/browse/ARROW-12739

For a manual workaround for now, I can only think of a way doing this
outside of arrow (for example in Python, you could use plain Python to zip
the arrays or use numpy to horizontally stack the arrays in a 2D array of
the correct shape, and then use those combined values to create the
ListArray).

Joris


On Fri, 4 Nov 2022 at 04:25, Jin Shang <[email protected]> wrote:

> Hi,
>
> Suppose I have several arrays of the same type T with the same length N. I
> would like to concatenate them to an array of type List<T> (or perhaps
> FixedSizeList<T, N> for better performance).
>
> For example,Input T = int32, [1, 2, 3], [4, 5, 6], [7, 8, 9] will have
> output List<int32> of size 3: [[1, 4, 7], [2, 5, 8], [3, 6, 9]].
>
> T can also be a nested type like T = List<int32> [[1, 2, 3], [4]] and
> [[5], [6, 7, 8, 9]] with output List<List<int32>> of size 2: [[[1, 2, 3],
> [5]], [[4], [6, 7, 8, 9]]].
>
> Conceptually, I want to “squeeze” multiple columns of a table to a single
> column of List type.
>
> Is there an existing utility function or compute kernel that does this?
>
> Thanks,
> Jin

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