Hi Pasha,
It would be helpful to know in which broader context you're asking. Are you trying to do something in particular? > i can't find any details on how to connect this > protocol with other libraries/applications. You use those libraries/applications' dedicated APIs. Just like in Python, when a library's API says "you can pass any object defining the buffer protocol for argument XXX", you can do just that. The C data interface is not an *API*. It defines a standard for exchanging data. How that data is exposed or consumed is up to third-parties. Regards Antoine. Le 20/10/2020 à 03:46, Wes McKinney a écrit : > hi Pasha, > > Copying dev@. > > You can see how DuckDB interacts with the pyarrow data structures by > the C interface here, maybe it's helpful > > https://github.com/cwida/duckdb/blob/master/tools/pythonpkg/duckdb_python.cpp > > We haven't defined a Python API (either C API level or Python API > level) so that objects can advertise that they support the Arrow C > interface -- it's a separate issue from the C interface itself (which > doesn't have anything specifically to do with Python), and I agree it > would probably be a good idea to have a standard way that we codify > and document . > > Thanks > Wes > > On Mon, Oct 19, 2020 at 12:34 PM Pasha Stetsenko <stpa...@gmail.com> wrote: >> >> Hi everybody, >> >> I've been reading http://arrow.apache.org/docs/format/CDataInterface.html, >> which has been >> "... inspired by the Python buffer protocol", and i can't find any details >> on how to connect this >> protocol with other libraries/applications. >> >> Here's what I mean: with the python buffer protocol, i can create a new type >> and set its >> `tp_as_buffer` field to a `PyBufferProcs` structure. This way any other >> library can call >> `PyObject_CheckBuffer()` on my object to check whether or not it supports >> the buffer interface, >> and then `PyObject_GetBuffer()` to use that interface. >> >> I could not find the corresponding mechanisms in the Arrow C data interface. >> For example, consider the "Exporting a simple int32 array" tutorial in the >> article above. After creating >> `export_int32_type()`, `release_int32_type()`, `export_int32_array()`, >> `release_int32_array()` >> -- how do i announce to the world that these functions are available? >> Conversely, if i want to >> talk to an Arrow Table via this interface -- where do i find the endpoints >> that return >> `ArrowSchema` and `ArrowArray` structures? >> >> (I understand that there is an additional, more complicated API for >> accessing arrow objects http://arrow.apache.org/docs/python/extending.html, >> but this seems to be a completely different >> API than what CDataInterface describes).
