Hi!
table.column('a').chunk(0).dictionary returns dictionary values as an array
that you can map...
Then you can construct new Dictionary Type columns from the mapped values
and table.column('a').chunk(0).indices
using pa.DictionaryArray.from_arrays
BR
J
niedz., 28 kwi 2024 o 20:19 Laurent Gautier <[email protected]> napisał(a):
> Hi,
>
> Is there a way to cast an Array of data type DictionaryType ( for example,
> I have DictionaryType(dictionary<values=large_string, indices=uint32,
> ordered=0>)) into integers (the indices) and retrieve the mapping (string
> -> integer)?
>
> I cannot find anything about this in the documentation. For the first ask
> (cast to integers), trying to cast does not work:
>
> >>> pyarrow.compute.cast(foo, pyarrow.int32())
> ArrowInvalid: Failed to parse string: 'Some String' as a scalar of type
> int32
>
>
> Best,
>
>
> Laurent
>
>
