You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@arrow.apache.org by "Ilya Orson Sandoval (Jira)" <ji...@apache.org> on 2020/03/13 18:55:00 UTC
[jira] [Created] (ARROW-8115) [Python] NaT not handled correctly
when writing
Ilya Orson Sandoval created ARROW-8115:
------------------------------------------
Summary: [Python] NaT not handled correctly when writing
Key: ARROW-8115
URL: https://issues.apache.org/jira/browse/ARROW-8115
Project: Apache Arrow
Issue Type: Bug
Environment: <details>
[paste the output of ``pd.show_versions()`` here below this line]
INSTALLED VERSIONS
------------------
commit : None
python : 3.7.4.final.0
python-bits : 64
OS : Windows
OS-release : 10
machine : AMD64
processor : Intel64 Family 6 Model 60 Stepping 3, GenuineIntel
byteorder : little
LC_ALL : None
LANG : None
LOCALE : None.None
pandas : 1.0.1
numpy : 1.18.1
pytz : 2019.3
dateutil : 2.8.0
pip : 20.0.2
setuptools : 45.2.0.post20200210
Cython : None
pytest : 5.3.5
hypothesis : None
sphinx : None
blosc : None
feather : None
xlsxwriter : None
lxml.etree : 4.4.2
html5lib : 1.0.1
pymysql : None
psycopg2 : None
jinja2 : 2.11.1
IPython : 7.12.0
pandas_datareader: None
bs4 : 4.8.1
bottleneck : None
fastparquet : None
gcsfs : None
lxml.etree : 4.4.2
matplotlib : 3.1.2
numexpr : None
odfpy : None
openpyxl : 3.0.3
pandas_gbq : None
pyarrow : 0.16.0
pytables : None
pytest : 5.3.5
pyxlsb : None
s3fs : 0.4.0
scipy : None
sqlalchemy : None
tables : None
tabulate : None
xarray : None
xlrd : 1.2.0
xlwt : None
xlsxwriter : None
numba : None
</details>
Reporter: Ilya Orson Sandoval
#### Code Sample
```python
import pandas as pd
df = pd.DataFrame({"date": ["", "2019-05-01"]})
df.date = pd.to_datetime(df.date).dt.date
df.to_parquet("issue_NaT_parquet")
```
#### Problem description
The above gives me the following error:
<details>
> ---------------------------------------------------------------------------
> TypeError Traceback (most recent call last)
> <ipython-input-11-432405bef6ac> in <module>
> ----> 1 df.to_parquet("test.parquet")
>
> ~\AppData\Local\Continuum\miniconda3\lib\site-packages\pandas\util\_decorators.py in wrapper(*args, **kwargs)
> 212 else:
> 213 kwargs[new_arg_name] = new_arg_value
> --> 214 return func(*args, **kwargs)
> 215
> 216 return cast(F, wrapper)
>
> ~\AppData\Local\Continuum\miniconda3\lib\site-packages\pandas\core\frame.py in to_parquet(self, path, engine, compression, index, partition_cols, **kwargs)
>
> 2114 index=index,
> 2115 partition_cols=partition_cols,
> -> 2116 **kwargs,
> 2117 )
> 2118
>
> ~\AppData\Local\Continuum\miniconda3\lib\site-packages\pandas\io\parquet.py in to_parquet(df, path, engine, compression, index, partition_cols, **kwargs)
> 262 index=index,
> 263 partition_cols=partition_cols,
> --> 264 **kwargs,
> 265 )
> 266
>
> ~\AppData\Local\Continuum\miniconda3\lib\site-packages\pandas\io\parquet.py in write(self, df, path, compression, coerce_timestamps, index, partition_cols,
> **kwargs)
> 99 from_pandas_kwargs["preserve_index"] = index
> 100
> --> 101 table = self.api.Table.from_pandas(df, **from_pandas_kwargs)
> 102 if partition_cols is not None:
> 103 self.api.parquet.write_to_dataset(
>
> ~\AppData\Local\Continuum\miniconda3\lib\site-packages\pyarrow\table.pxi in pyarrow.lib.Table.from_pandas()
>
> ~\AppData\Local\Continuum\miniconda3\lib\site-packages\pyarrow\pandas_compat.py in dataframe_to_arrays(df, schema, preserve_index, nthreads, columns, safe)
>
> 573 if nthreads == 1:
> 574 arrays = [convert_column(c, f)
> --> 575 for c, f in zip(columns_to_convert, convert_fields)]
> 576 else:
> 577 from concurrent import futures
>
> ~\AppData\Local\Continuum\miniconda3\lib\site-packages\pyarrow\pandas_compat.py in <listcomp>(.0)
> 573 if nthreads == 1:
> 574 arrays = [convert_column(c, f)
> --> 575 for c, f in zip(columns_to_convert, convert_fields)]
> 576 else:
> 577 from concurrent import futures
>
> ~\AppData\Local\Continuum\miniconda3\lib\site-packages\pyarrow\pandas_compat.py in convert_column(col, field)
> 558
> 559 try:
> --> 560 result = pa.array(col, type=type_, from_pandas=True, safe=safe)
> 561 except (pa.ArrowInvalid,
> 562 pa.ArrowNotImplementedError,
>
> ~\AppData\Local\Continuum\miniconda3\lib\site-packages\pyarrow\array.pxi in pyarrow.lib.array()
>
> ~\AppData\Local\Continuum\miniconda3\lib\site-packages\pyarrow\array.pxi in pyarrow.lib._ndarray_to_array()
>
> TypeError: an integer is required (got type datetime.date)
</details>
#### Expected Output
Parquet with null values mixed with date values.
#### Output of ``pd.show_versions()``
--
This message was sent by Atlassian Jira
(v8.3.4#803005)