py-lua

Bridge between Python and Lua. This project has been started to provide easy binding between python and lua programming languages. Currently tested with lua version 5.4 and python.

Currently py-lua supports:

• Importing python module into lua program.
• Getting string, float, boolean and None data types from python.
• Convertion between python dict and lua table.
• Calling and extracting return values of functions with simple data types.
• Working with python generators and lua threads.
• Support to use Object Oriented Programming between the languages.

Example

using python inside lua

# mymodule.py
PI = 3.14
e = 2.71

def add(x, y):
    return x + y

def sub(x, y):
    return x - y

def concatenate(x, y):
    return x + y

class Rectangle:
    def __init__(self, x, y):
        self.x = x
        self.y = y

    def get_area(self):
        return self.x * self.y

    def __str__(self):
        return f"Rectangle(x={self.x}, y={self.y})"

-- main.lua
require("pylua")

pymodule = Python.PyLoad("mymodule")

print("12 + 13 = ", pymodule.add(12, 13))
-- 12 + 13 = 25
print("e - pi = ", pymodule.sub(pymodule.PI, pymodule.e))
-- 3.17 - 2.71 = 0.43
print(pymodule.concatenate("Lua loves ", "Python"))
-- Lua loves Python

rect = pymodule.Rectangle(4, 6)
print(rect.get_area())
-- 24
print(tostring(rect))
-- Rectangle(x=4.0, y=6.0)

Using lua inside python

-- mymodule.lua

function celsius_to_fahrenheit(x)
    return (x * 1.8) + 32
end

function fahrenheit_to_celsius(x)
    return (x - 32) * .5556
end

# main.py
import pylua
    
lua_module = pylua.LuaLoad("mymodule.lua")

ctf_40 = lua_module.celsius_to_fahrenheit(40)
ftc_n40 = lua_module.fahrenheit_to_celsius(-40)

print(f"{ctf_40 = }, {ftc_n40 = }") # ctf_40 = 104.0, ftc_n40 = -40.0032

Building

To compile py-lua. First install the required dependencies:

• python3
• lua5.4
• premake5
• gcc (linux)
• Visual Studio Code (windows)

Clone the repository

git clone https://github.com/Vipul-Cariappa/py-lua.git

Update premake5.lua file: Replace /path/to/python/header and /path/to/lua/header with actual header paths and replace /path/to/python/shared_libraries and /path/to/lua/shared_libraries with actual paths to shared libraries.

After updating paths run premake with desired action:

premake5 [action]

You can now use compiler of your choice to build the pylua shared library.

Copy the shared library pylua.so file to the working directory of your project.

If you face any problems while building please ask for help here.

Contribution

All contributions are welcomed. You can fork the project and create new PR, if you want to contribute. If the PR is related to a bud, creating a issue before creating the PR is recommended.

Discussions

If you have any problems or have any feature request please feel free to post new discussion. I will try to get at all of them.