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https://issues.apache.org/jira/browse/ARROW-2714?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16519174#comment-16519174
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Wes McKinney commented on ARROW-2714:
-------------------------------------
The Tensor classes are independent from the columnar data structures, though
they reuse pieces of metadata, metadata serialization, memory management, and
IPC.
The purpose of adding these to the library was to have in-memory data
structures for handling Tensor/ndarray data and metadata that "plug in" to the
rest of the Arrow C++ system (Plasma store, IO subsystem, memory pools,
buffers, etc.).
Theoretically you could return a Tensor when creating a non-contiguous slice of
an Array; in light of the above, I don't think that would be intuitive.
When we started the project, our focus was creating an open standard for
in-memory columnar data, a hitherto unsolved problem. The project's scope has
expanded into peripheral problems in the same domain in the meantime (with the
mantra of creating interoperable components, a use-what-you-need development
platform for system developers). I think this aspect of the project could be
better documented / advertised, since the project's initial focus on the
columnar standard has given some the mistaken impression that we are not
interested in any work outside of that.
> [C++/Python] Variable step size slicing for arrays
> --------------------------------------------------
>
> Key: ARROW-2714
> URL: https://issues.apache.org/jira/browse/ARROW-2714
> Project: Apache Arrow
> Issue Type: New Feature
> Components: C++, Python
> Reporter: Florian Jetter
> Priority: Minor
>
> Array slicing should support variable step sizes
> The current behavior raises an {{IndexError}}, e.g.
> {code}
> In [8]: import pyarrow as pa
> In [9]: pa.array([1, 2, 3])[::-1]
> ---------------------------------------------------------------------------
> IndexError Traceback (most recent call last)
> <ipython-input-9-20da5f9ab67a> in <module>()
> ----> 1 pa.array([1, 2, 3])[::-1]
> array.pxi in pyarrow.lib.Array.__getitem__()
> array.pxi in pyarrow.lib._normalize_slice()
> IndexError: only slices with step 1 supported
> {code}
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