Hi, Colin.
I'm sorry, my bad. I have tried the exec node without the full path to Python and it didn't work. So I think it's as you say: the path in node-red is different to the path from the terminal. I'm not quite sure how you change path in node-red though. I might have to do some Googling in that case.
I'm not sure, but besides Window's generated folder in the "Users" folder (Public, and Default), I'm the only user on my computer. Both node-red's and Python's directory is under my user folder though. Here's their directory:
C:\Users\my_name.node-red
C:\Users\my_name\AppData\Local\Programs\Python\Python37
