boost::python: Python list to std::vector

To make your C++ method accept Python lists you should use boost::python::list

void massadd(boost::python::list& ns){    for (int i = 0; i < len(ns); ++i)    {        add(boost::python::extract<double>(ns[i]));    }}

Here's what I use:

#include <boost/python/stl_iterator.hpp>namespace py = boost::python;template< typename T >inlinestd::vector< T > to_std_vector( const py::object& iterable ){    return std::vector< T >( py::stl_input_iterator< T >( iterable ),                             py::stl_input_iterator< T >( ) );}

Should you find the input type (py::object) too liberal, feel free to specify stricter types (py::list in your case).

Based on the above answers I created an example of accessing python lists in C++ as well as returning a python list from a C++ function:

#include <boost/python.hpp>#include <string>namespace py = boost::python;// dummy classclass drow{    public:        std::string word;        drow(py::list words);        py::list get_chars();};// example of passing python list as argument (to constructor)drow::drow(py::list l){    std::string w;    std::string token;    for (int i = 0; i < len(l) ; i++){        token = py::extract<std::string>(l[i]);        w += token;    }    this -> word = w;}// example of returning a python listpy::list drow::get_chars(){    py::list char_vec;    for (auto c : word){        char_vec.append(c);    }    return char_vec;}// binding with pythonBOOST_PYTHON_MODULE(drow){    py::class_<drow>("drow", py::init<py::list>())        .def("get_chars", &drow::get_chars);}

For a build example and a test python script take a look here

Thank you Arlaharen & rdesgroppes for the pointers (pun not intended).