[jira] [Updated] (ARROW-11388) Dataset Timezone Handling

["Andy Douglas (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/ARROW-11388?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Andy Douglas updated ARROW-11388:
---------------------------------
    Description: 
I'm trying to write a pandas dataframe with a datetimeindex with timezone information to a pyarrow dataset but the timezone information doesn't seem to be written (apart from in the pandas metadata)

 

For example

 
{code:java}
import os
import pandas as pd
import numpy as np
import pyarrow as pa
import pyarrow.parquet as pq
import pyarrow.dataset as ds

from pathlib import Path

print(pa.__version__)
# create dummy dataframe with datetime index containing tz info
df = pd.DataFrame(
    dict(
        timestamp=pd.date_range("2021-01-01", freq="1T", periods=100, tz="US/Eastern"),
        x=np.arange(100),
     )
).set_index("timestamp")

test_dir = Path("test_dir")
table = pa.Table.from_pandas(df)
schema = table.schema

print(schema)
print(schema.pandas_metadata)

# warning - creates dir in cwd
pq.write_to_dataset(table, test_dir)

print(pq.ParquetFile(test_dir / os.listdir(test_dir)[0]).read())

# create dataset using schema from earlier
dataset = ds.dataset(test_dir, format="parquet", schema=schema)

# doesn't work
dataset.to_table()
{code}
 

 

Is this a bug or am I missing something?

Thanks

Andy

 

  was:
I'm trying to write a pandas dataframe with a datetimeindex with timezone information to a pyarrow dataset but the timezone information doesn't seem to be written (apart from in the pandas metadata)

 

For example

 
{code:java}
import os
import pandas as pd
import numpy as np
import pyarrow as pa
import pyarrow.parquet as pq
import pyarrow.dataset as ds
from pathlib import Path
print(pa.__version__)
# create dummy dataframe with datetime index containing tz info
df = pd.DataFrame(
    dict(
        timestamp=pd.date_range("2021-01-01", freq="1T", periods=100, tz="US/Eastern"),
        x=np.arange(100),
     )
).set_index("timestamp")
test_dir = Path("test_dir")
table = pa.Table.from_pandas(df)
schema = table.schema
print(schema)
print(schema.pandas_metadata)
pq.write_to_dataset(table, test_dir)
print(pq.ParquetFile(test_dir / os.listdir(test_dir)[0]).read())
dataset = ds.dataset(test_dir, format="parquet", schema=schema)
dataset.to_table()
{code}
 

 

Is this a bug or am I missing something?


Thanks

Andy

 


> Dataset Timezone Handling
> -------------------------
>
>                 Key: ARROW-11388
>                 URL: https://issues.apache.org/jira/browse/ARROW-11388
>             Project: Apache Arrow
>          Issue Type: Bug
>          Components: Python
>    Affects Versions: 2.0.0, 3.0.0
>            Reporter: Andy Douglas
>            Priority: Minor
>
> I'm trying to write a pandas dataframe with a datetimeindex with timezone information to a pyarrow dataset but the timezone information doesn't seem to be written (apart from in the pandas metadata)
>  
> For example
>  
> {code:java}
> import os
> import pandas as pd
> import numpy as np
> import pyarrow as pa
> import pyarrow.parquet as pq
> import pyarrow.dataset as ds
> from pathlib import Path
> print(pa.__version__)
> # create dummy dataframe with datetime index containing tz info
> df = pd.DataFrame(
>     dict(
>         timestamp=pd.date_range("2021-01-01", freq="1T", periods=100, tz="US/Eastern"),
>         x=np.arange(100),
>      )
> ).set_index("timestamp")
> test_dir = Path("test_dir")
> table = pa.Table.from_pandas(df)
> schema = table.schema
> print(schema)
> print(schema.pandas_metadata)
> # warning - creates dir in cwd
> pq.write_to_dataset(table, test_dir)
> print(pq.ParquetFile(test_dir / os.listdir(test_dir)[0]).read())
> # create dataset using schema from earlier
> dataset = ds.dataset(test_dir, format="parquet", schema=schema)
> # doesn't work
> dataset.to_table()
> {code}
>  
>  
> Is this a bug or am I missing something?
> Thanks
> Andy
>  



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