extracting pyarrow table with `DictionaryArray` field fails

[jorritsandbrink]

dlt version

dlt 1.3.1a1

Describe the problem

ValueError when running pipe.extract on pyarrow table with DictionaryArray field:

Traceback (most recent call last):
  File "/home/j/repos/dlt/dlt/pipeline/pipeline.py", line 468, in extract
    self._extract_source(
  File "/home/j/repos/dlt/dlt/pipeline/pipeline.py", line 1238, in _extract_source
    load_id = extract.extract(
  File "/home/j/repos/dlt/dlt/extract/extract.py", line 417, in extract
    self._extract_single_source(
  File "/home/j/repos/dlt/dlt/extract/extract.py", line 349, in _extract_single_source
    extractors[item_format].write_items(
  File "/home/j/repos/dlt/dlt/extract/extractors.py", line 333, in write_items
    super().write_items(resource, items, meta)
  File "/home/j/repos/dlt/dlt/extract/extractors.py", line 138, in write_items
    self._write_to_static_table(resource, table_name, items, meta)
  File "/home/j/repos/dlt/dlt/extract/extractors.py", line 340, in _write_to_static_table
    super()._write_to_static_table(resource, table_name, items, meta)
  File "/home/j/repos/dlt/dlt/extract/extractors.py", line 217, in _write_to_static_table
    items = self._compute_and_update_table(resource, table_name, items, meta)
  File "/home/j/repos/dlt/dlt/extract/extractors.py", line 455, in _compute_and_update_table
    items = super()._compute_and_update_table(resource, table_name, items, meta)
  File "/home/j/repos/dlt/dlt/extract/extractors.py", line 236, in _compute_and_update_table
    computed_table = self._compute_table(resource, items, meta)
  File "/home/j/repos/dlt/dlt/extract/extractors.py", line 414, in _compute_table
    arrow_table["columns"] = pyarrow.py_arrow_to_table_schema_columns(item.schema)
  File "/home/j/repos/dlt/dlt/common/libs/pyarrow.py", line 402, in py_arrow_to_table_schema_columns
    **get_column_type_from_py_arrow(field.type),
  File "/home/j/repos/dlt/dlt/common/libs/pyarrow.py", line 187, in get_column_type_from_py_arrow
    raise ValueError(dtype)
ValueError: dictionary<values=string, indices=int8, ordered=0>

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/home/j/repos/dlt/mre.py", line 9, in <module>
    pipe.extract(table, table_name="bug")
  File "/home/j/repos/dlt/dlt/pipeline/pipeline.py", line 223, in _wrap
    step_info = f(self, *args, **kwargs)
  File "/home/j/repos/dlt/dlt/pipeline/pipeline.py", line 177, in _wrap
    rv = f(self, *args, **kwargs)
  File "/home/j/repos/dlt/dlt/pipeline/pipeline.py", line 163, in _wrap
    return f(self, *args, **kwargs)
  File "/home/j/repos/dlt/dlt/pipeline/pipeline.py", line 272, in _wrap
    return f(self, *args, **kwargs)
  File "/home/j/repos/dlt/dlt/pipeline/pipeline.py", line 489, in extract
    raise PipelineStepFailed(
dlt.pipeline.exceptions.PipelineStepFailed: Pipeline execution failed at stage extract when processing package 1730705003.55613 with exception:

<class 'ValueError'>
dictionary<values=string, indices=int8, ordered=0>

Expected behavior

Successful extract.

Steps to reproduce

import dlt
import pyarrow as pa

# create pyarrow table with DictionaryArray field
array = pa.array(["a", "b", "c"], type=pa.dictionary(pa.int8(), pa.string()))
table = pa.table({"foo": array})

# try to extract with dlt pipeline
pipe = dlt.pipeline(destination="filesystem")
pipe.extract(table, table_name="bug")

# result: <class 'ValueError'> dictionary<values=string, indices=int8, ordered=0>

Operating system

Linux

Runtime environment

Local

Python version

3.9

dlt data source

pyarrow table

dlt destination

Filesystem & buckets

Other deployment details

No response

Additional information

No response

[jorritsandbrink]

Issue is that get_column_type_from_py_arrow function does not have an if-branch for dictionary types.