On Dec 28, 12:45 am, "Daniel Fetchinson" <fetchin...@googlemail.com> wrote: > I'm trying to write an extension module in C which contains a single > function with the following prototype: > > void func( int N, int * arg1, int * arg2, int * ret ); > > Here arg1 and arg2 are length N arrays, and the function computes ret > which is also an N length array. From python I'd like to call this > function as > > ret = func( [ 1, 2, 3 ], [ 2, 3, 4] ) > > I've read through the docs > athttp://docs.python.org/extending/extending.htmland > alsohttp://docs.python.org/c-api/arg.htmlfrom which I learned how to pass > a fixed number of basic datatypes (int, float, string) from python to > C and back. What I don't know is how to pass an array back and forth. > > As far as I can see PyArg_ParseTuple is the function I should use for > converting the python arguments to C but the format string passed to > PyArg_ParseTuple can only be one of the basic data types ("s", "i", > etc) or a generic python object ("O"). > > Does this mean that I can only pass the arrays from python to C as > generic python objects and in a later operation I need to get the > elements from this generic python object, construct a C array and pass > that to the C function? Since I assume this is a frequent operation > I'd think there are some shortcuts, aren't there? Or what's the > simplest way of doing this? > > Cheers, > Daniel > > -- > Psss, psss, put it down! -http://www.cafepress.com/putitdown
Hi Daniel, Consider using this: http://docs.python.org/c-api/objbuffer.html This *IS* a shortcut, real shortcut. -- http://mail.python.org/mailman/listinfo/python-list
