C++ и Python: интеграция через pybind11

1pip install pybind11
2
3# Или через conda
4conda install -c conda-forge pybind11

1// math_bindings.cpp
2#include <pybind11/pybind11.h>
3#include <cmath>
4
5namespace py = pybind11;
6
7double add(double a, double b) {
8    return a + b;
9}
10
11double multiply(double a, double b) {
12    return a * b;
13}
14
15PYBIND11_MODULE(math_utils, m) {
16    m.doc() = "Math utility module";
17    m.def("add", &add, "Add two numbers");
18    m.def("multiply", &multiply, "Multiply two numbers");
19    m.def("sqrt", [](double x) { return std::sqrt(x); }, "Square root");
20}

1# setup.py
2from setuptools import setup
3from pybind11.setup_helpers import Pybind11Extension, build_ext
4
5ext_modules = [
6    Pybind11Extension(
7        "math_utils",
8        ["math_bindings.cpp"],
9    ),
10]
11
12setup(
13    name="math_utils",
14    ext_modules=ext_modules,
15    cmdclass={"build_ext": build_ext},
16)

1pip install -e .

1import math_utils
2
3print(math_utils.add(2, 3))      # 5.0
4print(math_utils.multiply(4, 5)) # 20.0
5print(math_utils.sqrt(16))       # 4.0

1#include <pybind11/pybind11.h>
2#include <string>
3
4namespace py = pybind11;
5
6class Animal {
7public:
8    Animal(const std::string& name) : name_(name) {}
9    virtual ~Animal() = default;
10    virtual std::string speak() const { return name_ + " speaks"; }
11    std::string name() const { return name_; }
12protected:
13    std::string name_;
14};
15
16class Dog : public Animal {
17public:
18    Dog(const std::string& name) : Animal(name) {}
19    std::string speak() const override { return name_ + " barks"; }
20};
21
22PYBIND11_MODULE(animal_module, m) {
23    py::class_<Animal>(m, "Animal")
24        .def(py::init<const std::string&>())
25        .def("speak", &Animal::speak)
26        .def("name", &Animal::name);
27    
28    py::class_<Dog, Animal>(m, "Dog")
29        .def(py::init<const std::string&>());
30}

1#include <pybind11/stl.h>
2
3std::vector<int> get_numbers() {
4    return {1, 2, 3, 4, 5};
5}
6
7std::map<std::string, int> get_scores() {
8    return {{"Alice", 95}, {"Bob", 87}};
9}
10
11PYBIND11_MODULE(stl_example, m) {
12    m.def("get_numbers", &get_numbers);
13    m.def("get_scores", &get_scores);
14}

1#include <pybind11/exceptions.h>
2
3void risky_operation() {
4    throw py::value_error("Something went wrong");
5}
6
7PYBIND11_MODULE(error_example, m) {
8    m.def("risky_operation", &risky_operation);
9}

1try:
2    error_example.risky_operation()
3except ValueError as e:
4    print(f"Error: {e}")

1#include <pybind11/numpy.h>
2
3py::array_t<double> process_array(py::array_t<double> input) {
4    auto buf = input.mutable_unchecked<2>();
5    auto result = py::array_t<double>({buf.shape(0), buf.shape(1)});
6    auto out = result.mutable_unchecked<2>();
7    
8    for (ssize_t i = 0; i < buf.shape(0); ++i) {
9        for (ssize_t j = 0; j < buf.shape(1); ++j) {
10            out(i, j) = buf(i, j) * 2;
11        }
12    }
13    return result;
14}