[ 
https://issues.apache.org/jira/browse/ARROW-2367?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16432606#comment-16432606
 ] 

Uwe L. Korn commented on ARROW-2367:
------------------------------------

The expected output would be that the resulting {{pyarrow.Table}} has a 
{{ChunkedArray}} instance for the respective column that consists of multiple 
chunks. Currently we only generate a single {{pa.Array}} and wrap that simply 
in a {{pa.ChunkedArray}}. Thus we are limited to what a single {{pa.Array}} can 
hold.

This should only happen on {{pa.Table.from_pandas()}} though. When a user calls 
{{pa.array()}} the current error is expected behaviour. We could add a second 
method {{pa.chunked_array()}} that would return a {{ChunkedArray}} with more 
than one chunk if necessary.

> ListArray has trouble with sizes greater than kMaximumCapacity
> --------------------------------------------------------------
>
>                 Key: ARROW-2367
>                 URL: https://issues.apache.org/jira/browse/ARROW-2367
>             Project: Apache Arrow
>          Issue Type: Bug
>          Components: Python
>    Affects Versions: 0.9.0
>            Reporter: Bryant Menn
>            Priority: Major
>
> When creating a Pandas dataframe with lists as elements as a column the 
> following error occurs when converting to a {{pyarrow.Table}} object.
> {code}
> Traceback (most recent call last):
> File "arrow-2227.py", line 16, in <module>
> arr = pa.array(df['strings'], from_pandas=True)
> File "array.pxi", line 177, in pyarrow.lib.array
> File "error.pxi", line 77, in pyarrow.lib.check_status
> File "error.pxi", line 77, in pyarrow.lib.check_status
> pyarrow.lib.ArrowInvalid: BinaryArray cannot contain more than 2147483646 
> bytes, have 2147483647
> {code}
> The following code was used to generate the error (adapted from ARROW-2227):
> {code}
> import pandas as pd
> import pyarrow as pa
> # Commented lines were used to test non-binary data types, both cause the 
> same error
> v1 = b'x' * 100000000
> v2 = b'x' * 147483646
> # v1 = 'x' * 100000000
> # v2 = 'x' * 147483646
> df = pd.DataFrame({
>      'strings': [[v1]] * 20 + [[v2]] + [[b'x']]
>      # 'strings': [[v1]] * 20 + [[v2]] + [['x']]
> })
> arr = pa.array(df['strings'], from_pandas=True)
> assert isinstance(arr, pa.ChunkedArray), type(arr)
> {code}
> Code was run using Python 3.6 with PyArrow installed from conda-forge on 
> macOS High Sierra.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

Reply via email to