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I recently began to experiment with Electron and SerialPort and hit a little snag when adding Angular (7+) in the mix.

So here's the problem:

I run the typical angular CLI commands to generate to the app. I add electron and electron-rebuild as dev dependencies. Then add SerialPort as a dependency.

Inside my app.component.ts -

lets see if I can make this clear... I'm a total Python beginner so bear with me, this is my first python program (though I'm familiar with basic scripting in a few other languages). I've been searching around for hours and I'm sure the answer to this is fairly simple but I have yet to get it to work properly.

I'm writing a code that should launch multiple commandline processes, and when each one finishes I want to update a cell in a QTableWidget. The table has a row for each process to run, and each row has a cell for the "status" of the process.

I can run this no problem if I just do a for loop, spawning one process per row using subprocess.call() however this is too linear and I would like to fire them all off at the same time and not hang the program for each loop cycle. I've been digging through the subprocess documentation and am having a really hard time with it. I understand that I need to use subprocess.Popen (which will prevent my program from hanging while the process runs, and thus I can spawn multiple instances). Where I run into trouble is getting the exit code back so that I can update my table, without hanging the program - for instance using subprocess.wait() followed by a subprocess.returncode still just sticks until the process completes. I need a sort of "when process completes, check the exit code and run a function that updates the QTableWidget."

I did find these two posts that seemed to get me going in the right direction, but didn't quite get me there:

Understanding Popen.communicate

How to get exit code when using Python subprocess communicate method?

Hopefully that made sense. Here's a simplified version of my code, I realize it is half-baked and half-broken but I've been screwing around with it for over an hour and I've lost track of a few things...