[jira] [Updated] (ARROW-7782) Losing index information when using write_to_dataset with partition_cols

["Ludwik Bielczynski (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/ARROW-7782?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Ludwik Bielczynski updated ARROW-7782:
--------------------------------------
    Description: 
One cannot save the index when using {{pyarrow.parquet.write_to_dataset()}} with given partition_cols arguments. Here I have created a minimal example which shows the issue:
{code:java}
 
from pathlib import Path
import pandas as pd
from pyarrow import Table
from pyarrow.parquet import write_to_dataset

path = Path('/home/user/trials')
file_name = 'local_database.parquet'
df = pd.DataFrame({"A": [1, 2, 3], "B": ['a', 'a', 'b']}, 
                  index=pd.Index(['a', 'b', 'c'], 
                  name='idx'))

table = Table.from_pandas(df)
write_to_dataset(table, 
                 str(path / file_name), 
                 partition_cols=['B']
                )
{code}
 

The issue is rather important for pandas and dask users.

  was:
One cannot save the index when using {{pyarrow.parquet.write_to_dataset()}} with given partition_cols arguments. Here I have created a minimal example which shows the issue:
{code:java}
 
from pathlib import Path
import pandas as pd
from pyarrow import Table
from pyarrow.parquet import write_to_dataset
path = Path('/home/ludwik/Documents/YieldPlanet/research/trials')
file_name = 'trial_pq.parquet'
df = pd.DataFrame({"A": [1, 2, 3], 
 "B": ['a', 'a', 'b']
 }, 
 index=pd.Index(['a', 'b', 'c'], name='idx'))

table = Table.from_pandas(df)
write_to_dataset(table, str(path / file_name), partition_cols=['B'],
 partition_filename_cb=None, filesystem=None)
{code}
 

The issue is rather important for pandas and dask users.


> Losing index information when using write_to_dataset with partition_cols
> ------------------------------------------------------------------------
>
>                 Key: ARROW-7782
>                 URL: https://issues.apache.org/jira/browse/ARROW-7782
>             Project: Apache Arrow
>          Issue Type: Bug
>         Environment: pyarrow==0.15.1
>            Reporter: Ludwik Bielczynski
>            Priority: Major
>
> One cannot save the index when using {{pyarrow.parquet.write_to_dataset()}} with given partition_cols arguments. Here I have created a minimal example which shows the issue:
> {code:java}
>  
> from pathlib import Path
> import pandas as pd
> from pyarrow import Table
> from pyarrow.parquet import write_to_dataset
> path = Path('/home/user/trials')
> file_name = 'local_database.parquet'
> df = pd.DataFrame({"A": [1, 2, 3], "B": ['a', 'a', 'b']}, 
>                   index=pd.Index(['a', 'b', 'c'], 
>                   name='idx'))
> table = Table.from_pandas(df)
> write_to_dataset(table, 
>                  str(path / file_name), 
>                  partition_cols=['B']
>                 )
> {code}
>  
> The issue is rather important for pandas and dask users.



--
This message was sent by Atlassian Jira
(v8.3.4#803005)