Re: [Discuss-gnuradio] vectors of vectors in python

[Michael Dickens]

On Feb 1, 2007, at 11:47 PM, Achilleas Anastasopoulos wrote:
> private:
>   std::vector< std::vector<int> > d_PS;
> public:
>   const std::vector< std::vector<int> > & PS () const { return d_PS; }

Here's a quick, partial answer.  According to the SWIG docs &  
tutorials, what one needs to do is something like (these could be in  
struct's of class'es instead):

typedef std::vector<int> VecInt;
typedef std::vector<VecInt> VecInt2;

Then in Python (after compilation via SWIG -> C++), something like:

>>> import VecStuff
>>> a = VecInt ([1 2 3])
>>> b = VecInt ([4 5 6])
>>> c = VecInt2 (a, b)

Please note that 'a' and 'b' above do -not- need to be the same  
length, not for C++ nor SWIG nor Python, since this is not a "matrix"  
but just a vector of vectors.

The exact details remain to be figured out.  The basic idea is that,  
in order for SWIG (and thus Python) to know what type of structure is  
being dealt with, one has to name all of the relevant parts of the  
structure.  Thus

std::vector< std::vector<int> > V2Int;

won't work because SWIG can't name the internal "std::vector<int>"  
data.  SWIG takes the approach of "separate and conquer".  Hope this  
helps! - MLD