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https://issues.apache.org/jira/browse/ARROW-13436?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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ASF GitHub Bot updated ARROW-13436:
-----------------------------------
    Labels: good-first-issue pull-request-available  (was: good-first-issue)

> [Python][Doc] Clarify what should be expected if read_table is passed an 
> empty list of columns
> ----------------------------------------------------------------------------------------------
>
>                 Key: ARROW-13436
>                 URL: https://issues.apache.org/jira/browse/ARROW-13436
>             Project: Apache Arrow
>          Issue Type: Bug
>          Components: Python
>            Reporter: Weston Pace
>            Assignee: Sasha Krassovsky
>            Priority: Major
>              Labels: good-first-issue, pull-request-available
>          Time Spent: 10m
>  Remaining Estimate: 0h
>
> The documentation for pyarrow.parquet.read_table states:
>  
>  * *columns* (_list_) – If not None, only these columns will be read from the 
> file. A column name may be a prefix of a nested field, e.g. ‘a’ will select 
> ‘a.b’, ‘a.c’, and ‘a.d.e’.
>  
> It is not clear what should be the expected result if columns is an empty 
> list.  In pyarrow 3.0 this read in all columns (as long as 
> use_legacy_dataset=False).  In pyarrow 4.0 this doesn't read in any columns.  
> I think this behavior (not reading in any columns) is the correct behavior 
> (since None can be used for all columns) but we should clarify that in the 
> docs.



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