Run python script on Raspbian desktop through ssh access

Question

I have a RaspberryPi with a PiTFT 3.5 display connected. The display is configured to mirror the HDMI output and the Pi is running Raspbian desktop.

Now what I am trying to do is to run a python program on the desktop but start it over the ssh connection. The problem is that when I just run my python script over the terminal as such:

sudo python3 /usr/local/project/main.py

it gives the following error:

_tkinter.TclError: no display name and no $DISPLAY environment variable

So is there a way of starting the python program on the desktop through ssh or maybe passing the display variable to Tkinter so that the program displays on my PiTFT screen.

Answer 1

Before you launch the script from ssh:

export DISPLAY=:0

There are other possible values but, presuming there is only one GUI user logged in on the pi, it will be :0, the first display. You can also get it directly from the desktop (echo $DISPLAY) -- but not from the ssh login.

• Mercury: Perfect it works, the only thing I had to change is to not run it as superuser and run your command and then it worked perfectly.
• goldilocks: $DISPLAY is an environment variable, if you are curious. The export command is a shell built-in.