I have worked a litte bit more on the watchdog script.
The scripts gets startet over subprocess.
The subprocesses managed in a dictionary to start/stop/restart
The whole function run in a thread so it dont block the main process and multiple watchdogs can be started.
Outcome is a phyton watchdog script with the following futures:
I have uploaded everything to github with example files and description.
You can find it here: Python-Watchdog on github
Thanks to everybody !