Error when attempting to create Python GUI using Tkinter: "no display name and no $DISPLAY environment variable"

Question

Sup,

• I am simply trying to use Tkinter (a Python GUI creator) to create a GUI on my Raspberry Pi.
• To start, I only want a GUI to show up on my screen. That's it!
• The code DOES work on my PC
• The code does NOT work on my Raspberry Pi

The entire script looks as follows:
(works on my PC, bringing up an empty GUI)

import Tkinter

root = Tkinter.Tk()

root.mainloop()

Trying to run the program in terminal as follows:

sudo python GUI.py

Produces the following error:

Traceback (most recent call last):

File "GUI.py", line 4, in root = Tkinter.Tk()

File "/usr/lib/python2.7/lib-tk/Tkinter.py", line 1817, in init

self.tk = _tkinter.create(screenName, baseName, className, interactive, wantobjects, useTk, sync, use)

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

Does anybody have any idea how I can resolve this issue? The error is produced under all of the following conditions:

• Direct HDMI to computer monitor
• DSI connection to touchscreen LCD
• SSH on computer monitor

For reference, if I type the following into my terminal:

echo $DISPLAY

An empty string gets printed, so I believe therein lies the problem

The following commands don't work either, which might shed light on the problem:

sudo apt-get update

startx

Answer 1

I solved it with these two commands:

export DISPLAY=0.0 xhost + 

Answer 2

Here is my solution. This works for SSH terminal, or crontab:

import Tkinter import sys import os if os.environ.get('DISPLAY','') == '': print('no display found. Using :0.0') os.environ.__setitem__('DISPLAY', ':0.0') #create main window master = Tkinter.Tk() master.title("tester") master.geometry("300x100") #make a label for the window label1 = Tkinter.Label(master, text='Hellooooo') # Lay out label label1.pack() # Run forever! master.mainloop() 

Answer 3

you have just to write: export MPLBACKEND="agg"