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https://issues.apache.org/jira/browse/ARROW-10344?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17217629#comment-17217629
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Gert Hulselmans commented on ARROW-10344:
-----------------------------------------
Thanks.
I can still do the filtering afterwards, so that is not a big problem.
Is there also something similar than pyarrow.dataset that allows combining
multiple feather files with one common column (index, which is in the same
order in all feather files) , while the other columns are different. It seems
only appending rows is supported by pyarrow.dataset).
{noformat}
feather1:
index col1 col2
1
...
n
feather2:
index col3 col4 col5
1
...
n
feather3:
index col6 col7 col 8
1
...
n
read feather1,2,3 as one combined table:
index col1 col2 col3 col4 col5 col6 col7 col 8
1
...
n
{noformat}
> [Python] Get all columns names (or schema) from Feather file, before loading
> whole Feather file
> ------------------------------------------------------------------------------------------------
>
> Key: ARROW-10344
> URL: https://issues.apache.org/jira/browse/ARROW-10344
> Project: Apache Arrow
> Issue Type: New Feature
> Components: Python
> Affects Versions: 1.0.1
> Reporter: Gert Hulselmans
> Priority: Major
>
> Is there a way to get all column names (or schema) from a Feather file before
> loading the full Feather file?
> My Feather files are big (like 100GB) and the names of the columns are
> different per analysis and can't be hard coded.
> {code:python}
> import pyarrow.feather as feather
> # Code here to check which columns are in the feather file.
> ...
> my_columns = ...
> # Result is pandas.DataFrame
> read_df = feather.read_feather('/path/to/file', columns=my_columns)
> # Result is pyarrow.Table
> read_arrow = feather.read_table('/path/to/file', columns=my_columns)
> {code}
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