Pybind11实践

安装 pybind11

$ brew install pybind11
# or
$ pip install pybind11

从 C++ 调用 Python

编辑 CMakeLists.txt 文件

project(pybind_demo)
cmake_minimum_required(VERSION 3.13)
set(CMAKE_CXX_STANDARD 14)    

include(FetchContent)
FetchContent_Declare(
    pybind11
    GIT_REPOSITORY https://github.com/pybind/pybind11.git
    GIT_TAG        v2.6.2
    GIT_SHALLOW    TRUE
)

FetchContent_MakeAvailable(pybind11)

add_executable(demo demo.cpp)
target_link_libraries(demo PRIVATE pybind11::embed)

编辑 demo.cpp 文件

#include <iostream>
#include <pybind11/embed.h>

namespace py = pybind11;
using namespace std;

int main()
{
    cout << "Hello PyBind World" << endl;

    // start the interpreter and keep it alive
    py::scoped_interpreter guard{}; 
    py::module math = py::module::import("math");
    py::object result = math.attr("sqrt")(25);
    std::cout << "Sqrt of 25 is: " << result.cast<float>() << std::endl;
}

从 Python 调用 C++

编辑 C++ 源文件

#include <pybind11/embed.h>

int multiply(int i, int j) {
    return i * j;
}

PYBIND11_MODULE(example, m) {
    m.doc() = "pybind11 example plugin"; // optional module docstring
    m.def("multiply", &multiply, "A function which multiplies two numbers");
}

编辑 CMakeLists.txt 文件

cmake_minimum_required(VERSION 3.13)
project(pybind_demo)
set(CMAKE_CXX_STANDARD 14)    

include(FetchContent)
FetchContent_Declare(
    pybind11
    GIT_REPOSITORY https://github.com/pybind/pybind11.git
    GIT_TAG        v2.6.2
    GIT_SHALLOW    TRUE
)

FetchContent_MakeAvailable(pybind11)

pybind11_add_module(example example.cpp)
target_compile_features(example PUBLIC cxx_std_14)
set_target_properties(example PROPERTIES SUFFIX ".so")

测试执行

import example
out = example.multiply(3, 2)
print("Multiply product is: %s" % out)

Citing

1. Calling Python and C++ Code using PyBind