[jira] [Created] (ARROW-5139) [Python/C++] Empty column selection no longer restores index

["Florian Jetter (JIRA)" <ji...@apache.org>]

Florian Jetter created ARROW-5139:
-------------------------------------

             Summary: [Python/C++] Empty column selection no longer restores index
                 Key: ARROW-5139
                 URL: https://issues.apache.org/jira/browse/ARROW-5139
             Project: Apache Arrow
          Issue Type: Bug
            Reporter: Florian Jetter


The index of a dataframe is no longer reconstructed when using empty column selection. This is a regression to 0.12.1 and probably only happens for pd.RangeIndex

{code:python}
import pandas as pd
import pyarrow as pa
import pyarrow.parquet as pq
from kartothek.serialization import ParquetSerializer
from storefact import get_store_from_url
print(pa.__version__)
df = pd.DataFrame(
    {"a": [1, 2]}
)
print(df.index)

table = pa.Table.from_pandas(df)
buf = pa.BufferOutputStream()
pq.write_table(table, buf)
reader = pa.BufferReader(buf.getvalue().to_pybytes())
table_restored = pq.read_pandas(reader, columns=[])
df_restored = table_restored.to_pandas()
print(len(df_restored))
{code}



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