Imagine a python script that will take a long time to run, what will happen if I modify it while it's running? Will the result be different?
Nothing, because Python precompiles your script into a PYC file and launches that.
However, if some kind of exception occurs, you may get a slightly misleading explanation, because line X may have different code than before you started the script.
What will happen if I modify a Python script while it's running?