Never mind, it's always happening when I ask for help.
This was the solution:
os.execute ("runuser -l pi -c \'python /home/pi/online_radio.py " .. devicechanged['OnlineRadio'] .. " &> /dev/null'")

Hello,

I have python script with list of online radio stations.
Python script takes one argument, like so: "python_script.py OnlineRadioStationName".
This works fine when executed in shell, but I have a problem linking this script to domoticz.

Here is the domoticz lua script:
commandArray ...