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May 14, 2021
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Update documentation to better reflect how PyArrow interoperability works #634

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2512ac8
Mention incompat with pyarrow >= 2.0; minor formatting fixes
AndreiBarsan May 12, 2021
aabb418
Fix rst link syntax
AndreiBarsan May 12, 2021
a0e2aa5
Replace warning with doc clarification
AndreiBarsan May 13, 2021
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21 changes: 14 additions & 7 deletions docs/source/features.rst
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Expand Up @@ -94,13 +94,20 @@ object.
PyArrow integration
-------------------

`pyarrow`_ has its own internal idea of what a file-system is (``pyarrow.filesystem.FileSystem``),
`pyarrow`_ has its own internal idea of what a file-system is (``pyarrow.fs.FileSystem``),
and some functions, particularly the loading of parquet, require that the target be compatible.
As it happens, the design of the file-system interface in ``pyarrow`` *is* compatible with `fsspec`
(this is not by accident). Therefore at import time, ``fsspec`` checks for the existence of
``pyarrow``, and, if found, adds it to the superclasses of the spec base-class. In this manner,
all ``fsspec``-derived file-systems are also pyarrow file-systems, and can be used by pyarrow
functions.
As it happens, the design of the file-system interface in ``pyarrow`` *is* compatible with ``fsspec``
(this is not by accident).

At import time, ``fsspec`` checks for the existence of ``pyarrow``, and, if ``pyarrow < 2.0`` is
found, adds its base filesystem to the superclasses of the spec base-class.
For ``pyarrow >= 2.0``, ``fsspec`` file systems can simply be passed to ``pyarrow`` functions
that expect ``pyarrow`` filesystems, and ``pyarrow`` `will automatically wrap them
<https://arrow.apache.org/docs/python/filesystems.html#using-fsspec-compatible-filesystems>`_.

In this manner, all ``fsspec``-derived file-systems are also ``pyarrow`` file-systems, and can be used
by ``pyarrow`` functions.


.. _pyarrow: https://arrow.apache.org/docs/python/

Expand Down Expand Up @@ -377,7 +384,7 @@ Obviously, you should only define default values that are appropriate for
a given file system implementation. INI files only support string values.

Alternatively, you can provide overrides with environment variables of
the style "FSSPEC_{protocol}_{kwargname}=value".
the style ``FSSPEC_{protocol}_{kwargname}=value``.

Configuration is determined in the following order, with later items winning:

Expand Down