pybind11 simple test

README.md

Wrapping C++ for Python

Your project

1. You should have the CMakeFiles.txt and the src folder to start.

The CMakeFiles.txt:

cmake_minimum_required(VERSION 3.4...3.18)
project(pimymath)

add_library(mymath STATIC src/mymath.cpp)
set_target_properties(mymath PROPERTIES POSITION_INDEPENDENT_CODE ON)

add_subdirectory(pybind11)
pybind11_add_module(pimymath src/binder.cpp)
target_link_libraries(pimymath PRIVATE mymath)

In src, you have 3 files:

• mymath.h
• mymath.cpp
• binder.cpp

// mathmath.h
#pragma once

int add(int i, int j) ;

// mathmath.cpp
#include "mymath.h"

int add(int i, int j) {
    return i + j;
}

// binder.cpp
#include <pybind11/pybind11.h>
#include "mymath.h"

#define STRINGIFY(x) #x
#define MACRO_STRINGIFY(x) STRINGIFY(x)

namespace py = pybind11;

PYBIND11_MODULE(pimymath, m) {
    m.doc() = R"pbdoc(
        Pybind11 example plugin
        -----------------------

        .. currentmodule:: pimymath

        .. autosummary::
           :toctree: _generate

           add
           subtract
    )pbdoc";

    m.def("add", &add, R"pbdoc(
        Add two numbers

        Some other explanation about the add function.
    )pbdoc");

    m.def("subtract", [](int i, int j) { return i - j; }, R"pbdoc(
        Subtract two numbers

        Some other explanation about the subtract function.
    )pbdoc");

#ifdef VERSION_INFO
    m.attr("__version__") = MACRO_STRINGIFY(VERSION_INFO);
#else
    m.attr("__version__") = "dev";
#endif
}

Install pybind11 and Python env

1. Install pybind11

git clone https://github.com/pybind/pybind11.git

2. Install Python virtualenv (see this link )

pip3 install virtualenv

3. Create a virtual env

python3 -m venv project_env

4. Activate the above set project_env virtual envirnonment

source project_env/bin/activate

Compile your pybind11 project

1. Create a folder build and go inside

mkdir build && cd build

2. Type

cmake ..

3. Compile your dynamic lib:

make mymath

4. Then, the Python wrapping

make pimymath

5. Test your project

>>> import pimymath
>>> pimymath.add(1,2)
3
>>> pimymath.subtract(1,2)
-1
>>> quit()

References

1. This video
2. This article