Xlib.error.DisplayConnectionError on Ubuntu 18.04

Importing pyautogui in Python 3.7.2 in Ubuntu 18.04, generates a Xlib.error.DisplayConnectionError This error only occurs when running python with superuser privileges.

This the full traceback :-

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.7/site-packages/pyautogui/__init__.py", line 152, in <module>
    from . import _pyautogui_x11 as platformModule
  File "/usr/local/lib/python3.7/site-packages/pyautogui/_pyautogui_x11.py", line 160, in <module>
    _display = Display(os.environ['DISPLAY'])
  File "/usr/local/lib/python3.7/site-packages/Xlib/display.py", line 89, in __init__
    self.display = _BaseDisplay(display)
  File "/usr/local/lib/python3.7/site-packages/Xlib/display.py", line 71, in __init__
    protocol_display.Display.__init__(self, *args, **keys)
  File "/usr/local/lib/python3.7/site-packages/Xlib/protocol/display.py", line 167, in __init__
    raise error.DisplayConnectionError(self.display_name, r.reason)
Xlib.error.DisplayConnectionError: Can't connect to display ":0": b'No protocol specified\n

Steps to reproduce:-

• run sudo python3 in the terminal
• run import pyautoguiinside the python 3 shell

[iojcde]

Try https://github.com/mooz/xkeysnail/blob/master/README.md (look at usage section)

worked for me.

[Axaxin]

Same issue on ubuntu 20.04 python 3.8.10 system is on a VM, connect via noVNC… i think this is very common situation using linux, isnt it?

ok, issue resolve by installing python-tk (not python3-tk), then restart terminal or system, then it works. As the installation guide, i did install acrot, python3-tk and python3-dev, but it turn out not working, I’m not sure if I had restarted terminal right after these packs install, but I did restart after python-tk, then everything work.

Not sure if both python3-tk and python-tk are needed, or just python-tk alone.