Chatbot with node.js and python for NLP

Question

I'm actually working on a chatbot project which must talk 2 languages (Dialectic Moroccan and french) , i'm willing to build the bot with node.js and host it in a server and build an NLP with python from scratch then link both of codes .

Do you have any idea of how can i integrate python code to a node.js code?

Answer 1

You can create an Express server with endpoints that make calls to your NLP backend (written in Python) and retrieve their outputs.

How it could be implemented

Some Assumptions

Here, I'll assume that you intend to send the user's input text from your NodeJS server to your Python NLP backend to be translated & sent back to your NodeJS server as a valid response.

The Plan

Let's say you have an endpoint on your Express server called http://localhost:3000/Morrocan_NLP?text=mytexttotranslate. We're going to feed the query parameter text = "mytexttotranslate" to a Python script that'll receive it at the /Morrocan_NLP endpoint. This Python script will then process that piece of text and send it back to your NodeJS Express server.

To do that, you could set up a valid route in your NodeJS Express app and invoke the relevant Python script from that using a child process Here's a hypothetical code example to showcase this interaction:

// Setting up your Express server
const express = require('express');
const app = express();

// Step 1: 
// Set up the /Morrocan_NLP Express route
app.get('/Morrocan_NLP', invokePythonMorrocanTranslator);

// Step 2: 
// Create a callback function that handles requests to the '/Morrocan_NLP' endpoint
function invokePythonMorrocanTranslator(req, res) {

    // Importing Node's 'child_process' module to spin up a child process. 
    // There are other ways to create a child process but we'll use the 
    // simple spawn function here.
    var spawn = require("child_process").spawn;

    // The spawned python process which takes 2 arguments, the name of the 
    // python script to invoke and the query parameter text = "mytexttotranslate"
    var process = spawn('python', 
        [
            "./morrocan_nlp.py"
            req.query.text
        ]
    );

    // Step 3:
    // Listen for data output from stdout, in this case, from "morrocan_nlp.py"
    process.stdout.on('data', function(data) {

        // Sends the output from "morrocan_nlp.py" back to the user
        res.send(data.toString());

    });

}

In your Python script (just a hypothetical one) that does Morrocan translation called morrocan_nlp.py, you'd have something like this to receive & process the NodeJS server's query and return the result to it.

import sys

# This is how you'll receive the queries from your NodeJS server
# Notice that sys.argv[1] refers to the 2nd argument of the list passed 
# into the spawn('python', ...) function in your NodeJS server code above
text_from_node_server = str(sys.argv[1])

# perform_translation here is a function I made up that 
# translates any text into Morrocan
translated_text = perform_translation(text_from_node_server)

# return your processed text to the NodeJS server via stdout
print(translated_text)
sys.stdout.flush()

External resources

This is a basic way of communicating between NodeJS server <--> Python script which, however, might not be the most scalable and efficient way if you're builing a large-scale application. So I'd like to recommend you to refer to this article which contains a step-by-step tutorial on how to integrate NodeJS and Python in other more reliable ways as well. I really hope this has helped you or any other person reading this to get started!