I have a couple of headless pi 3's doing various work. I generally access these units with my cell phone over VNC app on Andriod. Sometimes, if the cell reception is poor and I connect to the pi I loose the connection. When this happens VNC does not get released properly on the pi. After that point, I can no longer connect to the pi through VNC. It gives me a connection error. The only way to clear this fault is to restart the pi, sometimes this is not practical. Is there a way to monitor VNC and restart it with a Python 3 script using os.system("?????").