[jira] [Created] (ARROW-6882) cannot create a chunked_array from dictionary_encoding result

["Artem KOZHEVNIKOV (Jira)" <ji...@apache.org>]

Artem KOZHEVNIKOV created ARROW-6882:
----------------------------------------

             Summary: cannot create a chunked_array from dictionary_encoding result
                 Key: ARROW-6882
                 URL: https://issues.apache.org/jira/browse/ARROW-6882
             Project: Apache Arrow
          Issue Type: Bug
          Components: Python
    Affects Versions: 0.15.0
            Reporter: Artem KOZHEVNIKOV


I've experienced a strange error raise when trying to apply `pa.chunked_array` directly on the indices of dictionary_encoding (code is below). Making a memory view solves the problem.
{code:python}
import pyarrow as pa
ca = pa.array(['a', 'a', 'b', 'b', 'c'])                                                                                           
fca = ca.dictionary_encode()                                                                                                       
fca.indices                                                                                                                        
<pyarrow.lib.Int32Array object at 0x1250fb888>
[
  0,
  0,
  1,
  1,
  2
]

pa.chunked_array([fca.indices])                                                                                                    
---------------------------------------------------------------------------
ArrowInvalid                              Traceback (most recent call last)
<ipython-input-44-71ca3b877e1c> in <module>
----> 1 pa.chunked_array([fca.indices])

~/Projects/miniconda3/envs/pyarrow/lib/python3.7/site-packages/pyarrow/table.pxi in pyarrow.lib.chunked_array()

~/Projects/miniconda3/envs/pyarrow/lib/python3.7/site-packages/pyarrow/error.pxi in pyarrow.lib.check_status()

ArrowInvalid: Unexpected dictionary values in array of type int32

# with another memory view it's  OK
pa.chunked_array([pa.Array.from_buffers(type=pa.int32(), length=len(fca.indices), buffers=fca.indices.buffers())])                 
Out[45]: 
<pyarrow.lib.ChunkedArray object at 0x12508dc78>
[
  [
    0,
    0,
    1,
    1,
    2
  ]
]
 {code}



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