{

// Initialize the Python runtime.

Py_Initialize();

// Initialize NumPy

np::initialize();

// Create an array in C++

int arr[] = {1,2,3,4} ;

// Create the ndarray in Python

np::ndarray py_array = np::from_data(arr, np::dtype::get_builtin<int>() , p::make_tuple(4), p::make_tuple(4), p::object());

// Print the ndarray that we just created, and the source C++ array

std::cout << "C++ array :" << std::endl ;

for (int j=0;j<4;j++)

{

std::cout << arr[j] << ' ' ;

}

std::cout << std::endl << "Python ndarray :" << p::extract<char const *>(p::str(py_array)) << std::endl;

// Change an element in the python ndarray

py_array[1] = 5 ;

// And see if the C++ container is changed or not

std::cout << "Is the change reflected in the C++ array used to create the ndarray ? " << std::endl ;

for (int j = 0;j<4 ; j++)

{

std::cout << arr[j] << ' ' ;

}

// Conversely, change it in C++

arr[2] = 8 ;

// And see if the changes are reflected in the Python ndarray

std::cout << std::endl << "Is the change reflected in the Python ndarray ?" << std::endl << p::extract<char const *>(p::str(py_array)) << std::endl;