@sdetweil - apologies not necessary - I am just happy you are able to look at it.

Hurrah! It works!

But even with that _ removed, I am still getting an odd error:

 TypeError: this.file is not a function

@sdetweil I found another, just up from that one - you have a missing ‘t’ in this line

this.config.command=this.config.command.slice(his.config.pythonName.length)

@sdetweil I have started fresh and am still having the same issue.
New install of buster, fully updated.
Installed all the MM and node successfully.
MM runs as expected.
Checked that python and python3 are both available to the OS.
Added the MMM-PythonPrint to the modules dir.

[12.04.2022 11:22.45.613] [LOG]   MMM-PythonPrint received a socket notification: CONFIG - Payload: [object Object]
[12.04.2022 11:22.45.619] [ERROR] Whoops! There was an uncaught exception...
[12.04.2022 11:22.45.640] [ERROR] ReferenceError: _this is not defined
    at Class.startit (/home/pi/MagicMirror/modules/MMM-PythonPrint/node_helper.js:27:24)
    at Class.socketNotificationReceived (/home/pi/MagicMirror/modules/MMM-PythonPrint/node_helper.js:46:9)
    at Socket.<anonymous> (/home/pi/MagicMirror/js/node_helper.js:109:11)
    at Socket.emit (node:events:390:28)
    at Socket.emitUntyped (/home/pi/MagicMirror/node_modules/socket.io/dist/typed-events.js:69:22)
    at /home/pi/MagicMirror/node_modules/socket.io/dist/socket.js:466:39
    at processTicksAndRejections (node:internal/process/task_queues:78:11)

This is my config section:

		{
			module:"MMM-PythonPrint",
			position:"center",
			disabled:false,
			config: {
				// name of the python process to execute (could be python3)
				pythonName: 'python',
				// command file in module folder
				// if false, YOU will provide the full path to the python program
				localfolder: true,

				// spawn a python pgm that writes over and over (timed maybe), but keeps running
				command: 'printit.py',
				repetative: true,

				// spawn a one time output  script, but relaunch it every cycletime milliseconds

				// repretative: false,
				// command: 'printitonce.py',
				cycletime: 2000,

				// print debugging messages from the node_helper
				debug: true
			}
		 },

@sdetweil super. thanks for the pointer.

@sdetweil it may just be quicker for me to learn how to do what my python code does in .js
It probably isn’t that complex. It is only reading stuff from web services and reporting it locally. I had hoped I could skip that stage, but I guess there are no short-cuts.

@sdetweil that works, but the setup refreshes itself by default, so it wouldn’t last too long.
I will work it through. Thanks

@sdetweil you are correct. It doesn’t have python installed with it.
My next challenge is to work out how to get that up and running.

Once I have it running I will get back to you on your module.

@sdetweil I have just had that lightbulb switch on in my head…

@sdetweil But if I exec into a bash console in the docker container, it doesn’t seem to have access to Python, so maybe that’s the problem.
It is all rather confusing. (More so from your end, no doubt)