I want to write a daemon in python which gets started via systemd.
I want to use Type=notify, this way I don't have to do the double fork magic.
According to the docs:
The reference implementation for this notification is provided by libsystemd-daemon.so
... how to do this with Python?
Probably, you could use sdnotify python module which is a pure-python implementation of sd_notify protocol. Actually, the protocol is rather simple, so the module implementation is quite short.
To use watchdog machinery you should add WatchdocSec=<smth> to the unit file, and then send WATCHDOG=1 messages on a regular basis from your service. Check Restart= option as well.