tknew tknew - 8 months ago 63
Node.js Question

Python process forked by NodeJS - Alternative to process.send() for Python?

I'm forking a Python script with NodeJS and when forked, by default, NodeJS create an IPC between this new process and the parent.

With NodeJS, to send message from a child to the parent I do

process.send({msg : 'toto'})

How can I do that with Python ?


Ok I found it, finally is quite easy. It's only about writing on the right file descriptor.

On the NodeJS side parameter, spawn your script like that :

var child = child_process.spawn('python', [''], {
  stdio:[null, null, null, 'ipc']

child.on('message', function(message) {
  console.log('Received message...');

As the 'ipc' channel is the 4rd parameter, you will have to write on the filedescriptor 3. On the Python side :

import os

os.write(3, '{"dt" : "This is a test"}" + "\n", "utf8")

Done. You will receive the message on the child.on('message' callback.

Cheers !