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Antoine Pitrou edited comment on ARROW-2646 at 6/29/18 2:36 PM: ---------------------------------------------------------------- The standard {{csv}} module has both a notion of "dialect" and additional {{**kwargs}} to each function so that you can override individual options. Intuitively, it allows accepting individual option arguments without listing and documenting them explicitly for each method. I tend to prefer the options object / dialect approach myself, but it's true I'm more in the library developer camp :-) was (Author: pitrou): The standard {{csv}} module has both a notion of "dialect" and addition {{**kwargs}} to each function to that you can override individual options. Intuitively, it allows accepting individual option arguments without listing and documenting them explicitly for each method. > [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 > Affects Versions: 0.9.0 > 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} -- This message was sent by Atlassian JIRA (v7.6.3#76005)