Stops a process by name if switched away from workspace

i3-stop

#!/usr/bin/env python3

import i3ipc
from sh import pkill

WNAME='browser'
PNAME='firefox'

def on_workspace(i3, e):
    if e.current.props.name == WNAME:
        pkill('-CONT', PNAME)
    else:
        pkill('-STOP', PNAME)

i3 = i3ipc.Connection()
i3.on('workspace::focus', on_workspace)

i3.main()