On Raspbian Jessie I'm writing a Python script automatically ran by systemd. As a SSCCE let's write a trivial Python script as a service:cat >/home/pi/service.py <<EOFfrom time import sleepsleep(99999)EOFThis is interruptible via SIGINT, so I setup the service like this and tell systemd SIGINT is the right way to close it:cat >/lib/systemd/system/python-service.service <<EOF[Unit]Description=Python service[Service]Type=simpleTTYPath=/dev/tty1StandardInput=ttyStandardOutput=ttyExecStart=/usr/bin/nohup /usr/bin/python /home/pi/service.pyKillSignal=SIGINTSuccessExitStatus=SIGINT[Install]WantedBy=multi-user.targetEOFI then setup systemd to launch this service:systemctl set-default multi-user.targetsystemctl daemon-reloadsystemctl enable python-service.serviceThe service is properly setup, ran, and can be stopped, but can't be restarted unless we reboot:# I first check that the service has been run at startup:pi@raspberrypi:~ $ systemctl status python-service.service  python-service.service - Python service   Loaded: loaded (/lib/systemd/system/python-service.service; enabled)   Active: active (running) since Mon 2017-01-09 01:56:47 UTC; 59s ago Main PID: 419 (python)   CGroup: /system.slice/python-service.service           419 /usr/bin/python /home/pi/service.py# It runs fine, now I stop itpi@raspberrypi:~ $ sudo systemctl stop python-service.service # Let's start it againpi@raspberrypi:~ $ sudo systemctl start python-service.service # And consult the current status, I assume the parenthesis mean there is an issuepi@raspberrypi:~ $ systemctl status python-service.service  python-service.service - Python service   Loaded: loaded (/lib/systemd/system/python-service.service; enabled)   Active: active (running) since Mon 2017-01-09 01:59:54 UTC; 2s ago Main PID: 833 ((nohup))   CGroup: /system.slice/python-service.service           833 (nohup)# And indeed no service.py is runningpi@raspberrypi:~ $ ps ax|grep service  839 pts/0    S+     0:00 grep --color=auto service
Systemd: Python service can't be restarted after stop
systemd;python;raspbian;services;daemon