How to Call a Python Function from Node.Js

Call a Python function from NodeJS

I guess you misunderstand the process of calling python. You are not calling python function in node directly but call the process to run a shell command that run ./ml.py and collect the console output.

If that's clear then the problem is obvious, you define the function in python but you forget to call it.

def testMLFunction():
    return "hello from Python"

print(testMLFunction())

By the way, I guess you are going to refer a machine learning algorithm as it is named as ML.
If that's the case, calling it from shell may be inefficient as loading a model could be time consuming and it will be loaded whenever you call it.

Instead, I recommend you also build a python server, and access these predicted result via internal http request.

How to call a specific python function from nodejs?

Write a short python program calling your function, and run it using the child_process module as shown in this thread. You'll be able to get standard output back.

How to call python script from NodeJs

There are multiple ways of doing this.

first way is by doing npm install python-shell

and here's the code

var PythonShell = require('python-shell');
//you can use error handling to see if there are any errors
PythonShell.run('my_script.py', options, function (err, results) { 
//your code

you can send a message to python shell using
pyshell.send('hello');

you can find the API reference here-
https://github.com/extrabacon/python-shell

second way - another package you can refer to is node python , you have to do npm install node-python
third way - you can refer to this question where you can find an example of using a child process-
How to invoke external scripts/programs from node.js

a few more references -
https://www.npmjs.com/package/python

if you want to use service-oriented architecture -
http://ianhinsdale.com/code/2013/12/08/communicating-between-nodejs-and-python/

Can I call a python function from a Node.js Google cloud function

Cloud Functions code runs inside a container that is set up for specific environments. For example, in your question, you are using the Node.js execution environment.

Your goal is to call a Python function (script) from Node.js. This would require the Python interpreter, libraries, and a correctly set up environment.

The Cloud Functions Node.js execution environment does not include the Python execution environment. Therefore the answer is not possible using Google provided execution environments.

If you would like to combine Node.js and Python, I recommend creating a custom Cloud Run container and deploying to Cloud Run, which is the big brother to Cloud Functions.

Call python function from node.js

Turns out there is a solution to this using python-shell. Details can be found here.