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https://issues.apache.org/jira/browse/ARROW-2646?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16512634#comment-16512634
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Uwe L. Korn commented on ARROW-2646:
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[~wesmckinn] I'm still not convinced that an Options object would work well
with Python users. Do you have an example of a Python project that uses it? I
would expect that users would much more favour kwargs are done in
Pandas/Matplotlib/… . While there are certain drawbacks for a library
developer, I think it will be much more appreciated by users.
> [Python] Pandas roundtrip for date objects
> ------------------------------------------
>
> Key: ARROW-2646
> URL: https://issues.apache.org/jira/browse/ARROW-2646
> Project: Apache Arrow
> Issue Type: Bug
> Components: Python
> Reporter: Florian Jetter
> Priority: Minor
> Fix For: 0.10.0
>
>
> Arrow currently casts date objects to nanosecond precision datetime objects.
> I'd like to have a way to preserve the type during a roundtrip
> {code}
> >>> import pandas as pd
> >>> import pyarrow as pa
> >>> import datetime
> >>> pa.date32().to_pandas_dtype()
> dtype('<M8[ns]')
> >>> df = pd.DataFrame({'date': [datetime.date(2018, 1, 1)]})
> >>> df.dtypes
> date object
> dtype: object
> >>> df_rountrip = pa.Table.from_pandas(df).to_pandas()
> >>> df_rountrip.dtypes
> date datetime64[ns]
> dtype: object
> {code}
> I'd expect something like this to work:
> {code}
> >>> import pandas.testing as pdt
> >>> df_rountrip = pa.Table.from_pandas(df).to_pandas(date_as_object=True)
> >>> pdt.assert_frame_equal(df_rountrip, df)
> {code}
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