Executing python in js - troublshooting/development

sdetweil

@beejay22 u can run python3 as the shebang. I was just giving example

your node_helper code was spawning python, not python3. I just copied what u did. u can put python3 in the spawn as well

custom.css, doesn’t matter, it’s empty so no harm

beejay22

Tried this (all I changed was “python” to “python3”):

const spawn = require("child_process").spawn
var NodeHelper = require("node_helper")

module.exports = NodeHelper.create({
  socketNotificationReceived: function(notification, payload) {
    switch(notification) {
      case "GIVE_ME_DATA":
        this.job()
        break
    }
  },
  job: function() {
    var process = spawn("python3", ["/home/pi/Desktop/realTester.py"])
    process.stdout.on("data", (data)=>{
      console.log(data)
      var result = String.fromCharCode.apply(null, new Uint16Array((data)))
      this.sendSocketNotification("HERE_IS_DATA", data)
    })
  }
})

And also changed pyscript to this (just added python3 to the shebang):

#!/usr/bin/python3
from bs4 import BeautifulSoup                                             
import requests                                                           

url=requests.get("https://www.whitehouse.gov/presidential-actions/")      
src=url.content                                                           
soup = BeautifulSoup(src, 'lxml')
for h2_tag in soup.findAll('h2'):
    a_tag = h2_tag.find('a')
    print(a_tag.string)

Also tested “python” again (not python3) in my node_helper along with the updated shebang as shown above

If custom.css file doesn’t matter I wonder why it’s giving this error… Have no clue what’s going on now lol

sdetweil

@beejay22 u need the fix for the data conversion… as well…

custom.css cause its a file t=hat MM force loads, and while the browser is unhappy (thus the error), the MM runtime doesn’t care WHY there was no data, missing file, empty file, don’t care there were no css updates…

i don’t do python so I can’t help much…

but you gotta put in the fixes I gave you for data…

  process.stdout.on("data", (data)=>{
      console.log(data.toString()) // debugging, log string     
      //var result = String.fromCharCode.apply(null, new Uint16Array((data)))
      this.sendSocketNotification("HERE_IS_DATA", data.toString())   // pass the string, module expects string
    })

beejay22

Sorry I copied the wrong node_helper.js file in my last post. This is how it looks like now:

//node_helper.js
const spawn = require("child_process").spawn
var NodeHelper = require("node_helper")

module.exports = NodeHelper.create({
  socketNotificationReceived: function(notification, payload) {
    switch(notification) {
      case "GIVE_ME_DATA":
        console.log("received notification")
        this.job()
        break
    }
  },
  job: function() {
    var process = spawn("python3", ["/home/pi/Desktop/realTester.py"])
    process.stdout.on("data", (data)=>{
      console.log(data.toString())    
      this.sendSocketNotification("HERE_IS_DATA", data.toString()) 
    })
  }
})

I was trying to test if I can at least print something to magic mirror without a pyscript… node_helper looks like this:

//node_helper.js
const spawn = require("child_process").spawn
var NodeHelper = require("node_helper")

module.exports = NodeHelper.create({
  socketNotificationReceived: function(notification, payload) {
    switch(notification) {
      case "GIVE_ME_DATA":
        console.log("received notification")
        this.job()
        break
    }
  },
  job: function() {
    var process = spawn("python3", ["/home/pi/Desktop/test.py"])
    process.stdout.on("data", (data)=>{
      data= "Hello World";
      console.log(data.toString())   
      this.sendSocketNotification("HERE_IS_DATA", data.toString())  
    })
  }
})

Hello World appears on MagicMirror but the test file that’s provided in the path (the test file just has: print(“this works”) does not so I’m not sure why I need to provide var process spawn if Hello World prints by itself… Anyways, I’m aware that there’s other ways to execute the child process however I’m not familiar with it. Please correct me if I’m wrong but can exec work in this situation as well? (pyscipt just prints out the latest titles when magic mirror restarts). I’m trying anything and everything at this point

And I added the default and start function to my core module although I don’t think I have to use it. This is how it looks like now:

/// MMM-Whitehouse.js - Core Module

Module.register("MMM-Whitehouse", {
  defaults: {},
  start: function () {},
  getDom: function() {
    var e = document.createElement("div")
    e.id = "DISPLAY"
    return e
  },
  notificationReceived: function(notification, payload, sender) {
    switch(notification) {
      case "DOM_OBJECTS_CREATED":
        var timer = setInterval(()=>{
          this.sendSocketNotification("GIVE_ME_DATA")
        }, 1000)
        break
    }
  },
  socketNotificationReceived: function(notification, payload) {
    switch(notification) {
      case "HERE_IS_DATA":
        var e = document.getElementById("DISPLAY")
        e.innerHTML = payload
        break
    }
  },
})

sdetweil

@beejay22 I don’t understand why u have trouble.

the 3 files I posted work together as u designed.

does your spawn(‘/use/bin/python’, [execname]) work to return the data.
console log to see

spawn and exec have different methods of returning the data. see the doc

Google search nodejs process spawn

beejay22

Did you try it with the pyscript? Or are you talking about it the core module, node_helper and config?

And okay

sdetweil

@beejay22 I am only working on inside MagicMirror

the spawn on.data() gets called when the pgm launched outputs to stdout. my print hello

of course I made sure the python script worked both ways, before showing that

beejay22

Okay. And yes it does return the data as output I believe

sdetweil

@beejay22 do you see this output from the node_helper in the terminal window where you do npm start?

console.log(data.toString())

from your python script