How to call a Python function from Lua?
lua, python
Solution
Sounds like Lunatic-Python does exactly what you're looking for. There's a fork of lunatic-python that's better maintained than the original. I've contributed several bug fixes to it myself awhile back.
So reusing your example,
Python code:
# sum.py
def sum_from_python(a, b):
return a + b
Lua code:
-- main.lua
py = require 'python'
sum_from_python = py.import "sum".sum_from_python
print( sum_from_python(2,3) )
Outputs:
lua main.lua
5
Most of the stuff works as you would expect but there are a few limitations to lunatic-python.
- It's not really thread-safe. Using the python threading library inside lua will have unexpected behavior.
- No way to call python functions with keyword arguments from lua. One idea is to emulate this in lua by passing a table but I never got around to implementing that.
- Unlike lupa, lunatic-python only has one global lua state and one python VM context. So you can't create multiple VM runtimes using lunatic-python.
As for lupa, note that it is a python module only, which means you must use python as the host language -- it does not support the use-case where lua is the "driving" language. For example, you won't be able to use lupa from a lua interpreter or from a C/C++ application that embeds lua. OTOH, Lunatic-Python can be driven from either side of the bridge.
Problem
I want to run a python script from my lua file. How can I achieve this? Example: Python code ``` #sum.py file def sum_from_python(a,b) return a+b ``` Lua code ``` --main.lua file print(sum_from_python(2,3)) ```