Short answer - no.
Long answer: You are actually calling a python interpreter. That interpreter loads the script.py and parses it.
If you change the script it has to reload the file and start from the beginning, since the interpreter has no way to know which part was changed.
Now if your goal is to simply signal python to reload/restart the script, you can wrap it into a shell-script:
pkill -f "$LINE"
trap stop 1
trap clean 9 15
You can now start that shell-script (in background, with nohup, if you like).
If you send a HUP signal to it, it will restart your python process.
If you kill the wrapper process the python script will terminate, too.
I did not test my script - but the idea should be clear.