How to connect Python to Node.js?

Question

I want to send to python a node.js variable, modify it with python and resend it to node.js, that is an example of my codes: Python

def change_input(variable):
    variable*=5
    #now send variable to node.js

Now the js code:

var variable=prompt("enter the variable");
#after the code was sended to thd python code, modified and resend:
document.write(variable)

How to circulates the variables between python and javascript?

Answer 1

Here is one way to do it, by spawning a child python process from within node.

test.js:

const { spawn } = require('child_process');
const p = spawn('python', ['yourscript.py', '1']);

p.stdout.on('data', (data) => {
  console.log(`stdout: ${data}`);
});

yourscript.py

import sys

def change_var(x):
    print('hello from python: {:d}'.format(int(x) + 2))

change_var(sys.argv[1])

output of running node ./test.js:

stdout: hello from python: 4

directory layout

➜  test tree
.
├── test.js
└── yourscript.py

0 directories, 2 files

related:

• https://nodejs.org/docs/latest-v8.x/api/child_process.html
• https://docs.python.org/2/library/sys.html#sys.argv
• https://docs.python.org/3/library/subprocess.html
• Calling an external command in Python