hi Tim, You can use the functions in
https://github.com/apache/arrow/blob/master/cpp/src/arrow/python/pyarrow.h You need to call "import_pyarrow()" from C++ before these APIs can be used. It's similar to the NumPy C API in that regard - Wes On Tue, Sep 10, 2019 at 4:13 PM Tim Paine <t.paine...@gmail.com> wrote: > > Hey all, following up on a question I asked on stack overflow > <https://stackoverflow.com/questions/57863751/how-to-convert-pyarrow-table-to-arrow-table-when-interfacing-between-pyarrow-in>. > > It seems there is some code > <https://arrow.apache.org/docs/python/extending.html#_CPPv412unwrap_tableP8PyObjectPNSt10shared_ptrI5TableEE> > in PyArrow’s C++ to convert from a PyArrow table to an Arrow table. The > problem with this is that my C++ library > <https://github.com/finos/perspective> is going to build and link against > Arrow on the C++ side rather than PyArrow side (because it will also be > consumed in WebAssembly), so I want to avoid also linking against PyArrow’s > copy of the arrow library. I also need to look for PyArrow’s header files, > which might conflict with the version in the local C++ code. > > My solution right now is to just assert that PyArrow version == Arrow version > and do some pruning (so I link against local libarrow and PyArrow’s > libarrow_python rather than use PyArrow’s libarrow), but ideally it would be > great if there was a clean way to hand a PyArrow Table over to C++ without > requiring the C++ to have PyArrow (e.g. using only a PyObject *). Please > forgive my ignorance/google skills if its already possible! > > unwrap_table code: > https://github.com/apache/arrow/blob/c39e3508f93ea41410c2ae17783054d05592dc0e/python/pyarrow/public-api.pxi#L310 > > <https://github.com/apache/arrow/blob/c39e3508f93ea41410c2ae17783054d05592dc0e/python/pyarrow/public-api.pxi#L310> > > library pruning: > https://github.com/finos/perspective/blob/python_arrow/cmake/modules/FindPyArrow.cmake#L53 > > <https://github.com/finos/perspective/blob/python_arrow/cmake/modules/FindPyArrow.cmake#L53> > > > > > Tim
