SWIG/python array inside structure

Question

I\'ve got a structure defined inside header.h that looks like :

typedef struct {
....
    int      icntl[40];
    double   cntl[15];
    int      *irn, *jcn;         


        

Answer 1

Have you considered using SWIG carrays?

In your header file:

typedef struct {
    int      icntl[40];
    double   cntl[15];
} some_struct_t;

Then, in your swig file:

%module example
%include "carrays.i"  
// ...
%array_class(int, intArray);
%array_class(double, doubleArray);

The Python looks like this:

icntl = example.intArray(40)
cntl = example.doubleArray(15)
for i in range(0, 40):
    icntl[i] = i
for i in range(0, 15):
    cntl[i] = i
st = example.some_struct_t()
st.icntl = icntl
st.cntl = cntl

You still can't set the structs directly. I write python wrapper code to hide the boilerplate.

array_class only works with basic types (int, double), if you need something else (e.g. uint8_t) you need to use array_functions, which have even more boilerplate, but they work.

http://www.swig.org/Doc3.0/SWIGDocumentation.html#Library_carrays