Arrow decimal type getting read as integer

[droher]

Bug Report

Steps to Reproduce:

Run this code in jupyterlab (duckdb version was 0.10.1 but should work on any recent version)

import perspective
import duckdb
import pyarrow as pa
import io

table = duckdb.sql("SELECT 3.14::DECIMAL AS decimal_col, 3.14::FLOAT AS float_col").arrow()
buffer = io.BytesIO()

with pa.ipc.new_file(buffer, table.schema) as writer:
    writer.write_table(table)

bytes_object = buffer.getvalue()

perspective_table = perspective.Table(bytes_object)
perspective.PerspectiveWidget(perspective_table)

Expected Result:

Values should be the same

Actual Result:

Decimal value is deserialized as the internal Arrow representation of a decimal type (an integer)

Environment:

perspective-python 2.10.0 running on Python 3.11, jupyterlab 3.6.5, MacOS 14.4.1.

Additional Context:

I first noticed this issue in the JS package but it was easier for me to create a replicable example in Python.

[timkpaine]

This is explicit, unsure if it's intentional https://github.com/finos/perspective/blob/055d5b3beb4599dda8f007f73923e8d451de4098/cpp/perspective/src/cpp/arrow_loader.cpp#L123

[texodus]

Perspective doesn't have internal support for decimal yet. We can change this behavior to cast to float instead which is probably more useful (for the purposes of data visualization at least).