dlib C++ Library - pybind_utils.h

// Copyright (C) 2013 Davis E. King (davis@dlib.net)
// License: Boost Software License See LICENSE.txt for the full license.
#ifndef DLIB_PYBIND_UtILS_Hh_
#define DLIB_PYBIND_UtILS_Hh_
#include <pybind11/pybind11.h>
#include <vector>
#include <string>
#include <dlib/serialize.h>
#include <array>
namespace py = pybind11;
namespace dlib
{
 template <typename T>
 std::vector<T> python_list_to_vector (
 const py::list& obj
 )
 /*!
 ensures
 - converts a python object into a std::vector<T> and returns it.
 !*/
 {
 std::vector<T> vect(len(obj));
 for (unsigned long i = 0; i < vect.size(); ++i)
 {
 vect[i] = obj[i].cast<T>();
 }
 return vect;
 }
 template <typename T,size_t N>
 std::array<T,N> python_list_to_array (
 const py::list& the_list
 )
 /*!
 ensures
 - converts a python object into a std::array<T,N> and returns it.
 !*/
 {
 DLIB_CASSERT(len(the_list) == N, "Expected a list of " << N << " things.");
 std::array<T,N> vect;
 for (unsigned long i = 0; i < vect.size(); ++i)
 {
 vect[i] = the_list[i].cast<T>();
 }
 return vect;
 }
 template <typename T>
 py::list vector_to_python_list (
 const std::vector<T>& vect
 )
 /*!
 ensures
 - converts a std::vector<T> into a python list object.
 !*/
 {
 py::list obj;
 for (unsigned long i = 0; i < vect.size(); ++i)
 obj.append(vect[i]);
 return obj;
 }
 template <typename T>
 void extend_vector_with_python_list (
 std::vector<T> &v,
 const py::list &l
 )
 /*!
 ensures
 - appends items from a python list to the end of std::vector<T>.
 !*/
 {
 for (const auto &item : l)
 v.push_back(item.cast<T>());
 }
// ----------------------------------------------------------------------------------------
 template <typename T>
 std::shared_ptr<T> load_object_from_file (
 const std::string& filename
 )
 /*!
 ensures
 - deserializes an object of type T from the given file and returns it.
 !*/
 {
 std::ifstream fin(filename.c_str(), std::ios::binary);
 if (!fin)
 throw dlib::error("Unable to open " + filename);
 auto obj = std::make_shared<T>();
 deserialize(*obj, fin);
 return obj;
 }
}
// ----------------------------------------------------------------------------------------
#endif // DLIB_PYBIND_UtILS_Hh_