Uwe Korn commented on ARROW-7066:

Would also be OK with this but we should make this clear somewhere in the 

> [Python] support returning ChunkedArray from __arrow_array__ ?
> --------------------------------------------------------------
>                 Key: ARROW-7066
>                 URL: https://issues.apache.org/jira/browse/ARROW-7066
>             Project: Apache Arrow
>          Issue Type: Improvement
>          Components: Python
>            Reporter: Joris Van den Bossche
>            Priority: Major
>              Labels: pull-request-available
>             Fix For: 1.0.0
>          Time Spent: 20m
>  Remaining Estimate: 0h
> The {{\_\_arrow_array\_\_}} protocol was added so that custom objects can 
> define how they should be converted to a pyarrow Array (similar to numpy's 
> {{\_\_array\_\_}}). This is then also used to support converting pandas 
> DataFrames with columns using pandas' ExtensionArrays to a pyarrow Table (if 
> the pandas ExtensionArray, such as nullable integer type, implements this 
> {{\_\_arrow_array\_\_}} method).
> This last use case could also be useful for fletcher 
> (https://github.com/xhochy/fletcher/, a package that implements pandas 
> ExtensionArrays that wrap pyarrow arrays, so they can be stored as is in a 
> pandas DataFrame).  
> However, fletcher stores ChunkedArrays in ExtensionArry / the columns of a 
> pandas DataFrame (to have a better mapping with a Table, where the columns 
> also consist of chunked arrays). While we currently require that the return 
> value of {{\_\_arrow_array\_\_}} is a pyarrow.Array.
> So I was wondering: could we relax this constraint and also allow 
> ChunkedArray as return value? 
> However, this protocol is currently called in the {{pa.array(..)}} function, 
> which probably should keep returning an Array (and not ChunkedArray in 
> certain cases).
> cc [~uwe]

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