PyXA script to run a Flow session only when a specific application (Notes) is open. Session stops when Notes is closed and restarts if the app is opened again.

run_flow_when_notes_open.py

import PyXA # Version 0.2.0
from time import sleep

flow = PyXA.Application("Flow")
in_session = False

while True:
    apps = PyXA.running_applications().localized_name()
    if "Notes" in apps and not in_session:
        flow.start()
        in_session = True
    elif "Notes" not in apps:
        flow.stop()
        in_session = False
    sleep(1)