how to set display variable for github codespaces to run gui applications especially for python gui programs

Question

I made a codespaces to work on gui based applications . But below error is showing. please guide me over this problem and how to make it work.

Traceback (most recent call last):
  File "/workspaces/CODSOFT/calculator.py", line 24, in <module>
    window = tk.Tk()
  File "/home/codespace/.python/current/lib/python3.10/tkinter/__init__.py", line 2299, in __init__
    self.tk = _tkinter.create(screenName, baseName, className, interactive, wantobjects, useTk, sync, use)
_tkinter.TclError: no display name and no $DISPLAY environment variable

Traceback (most recent call last):
  File "/workspaces/CODSOFT/calculator.py", line 24, in <module>
    window = tk.Tk()
  File "/home/codespace/.python/current/lib/python3.10/tkinter/__init__.py", line 2299, in __init__
    self.tk = _tkinter.create(screenName, baseName, className, interactive, wantobjects, useTk, sync, use)
_tkinter.TclError: no display name and no $DISPLAY environment variable