Hi Partha, I think this should do what you are looking for:
import pyarrow as pa
ty = pa.map_(pa.int32(), pa.float64())
out_ty = pa.struct([("keys", pa.list_(pa.int32())), ("values",
pa.list_(pa.float64()))])
arr = pa.array([[(1, 1.0), (2, 2.0)], [(3, 3.0)]], type=ty)
res = pa.StructArray.from_arrays(
[pa.ListArray.from_arrays(arr.offsets, arr.keys),
pa.ListArray.from_arrays(arr.offsets, arr.items)],
names=["keys", "values"]
)
assert res.type == out_ty
On Mon, Aug 1, 2022 at 11:29 AM Partha Dutta <[email protected]> wrote:
> I have a need to convert a MapArray type into a StructArray with separate
> elements for keys and values. I tried to extract the array from the table
> by column and use the corresponding chenks. What I ended up with are two
> arrays that are larger than the number of records in the table, so I can
> not replace the field.
>
> Is there a way to do this, short of iterating over each MapArray element
> one by one?
>
> --
> Partha Dutta
> [email protected]
>
