Swig — how to add a simple via-get-function attribute?

Question

I have a simple C structures that I want to make visible in Python interpreter:

struct OpenFile {
    int modified;
    const char *filename;
};
typedef struct OpenFile OpenFile;

struct OpenFiles {
    OpenFile *open_files;
    int count;
};

typedef struct OpenFiles OpenFiles;

Then I have a C function that allocates, populates and returns OpenFiles type:

OpenFiles get_open_files();

How should I expose the data in the interpreter?

I'm thinking about a readonly module attribute open_files that would be calling the above function on each access (the operation is cheap, no worries). However I don't know how to implement it?