I changed the font in Idle shell 3.8. Now i cant open Idle shell

This is the error its showing me. How do I change the format again?
I have tried re-installing the shell. it didnt work. please Help.

Traceback (most recent call last):
  File "/usr/bin/idle", line 5, in <module>
    main()
  File "/usr/lib/python3.8/idlelib/pyshell.py", line 1516, in main
    shell = flist.open_shell()
  File "/usr/lib/python3.8/idlelib/pyshell.py", line 329, in open_shell
    self.pyshell = PyShell(self)
  File "/usr/lib/python3.8/idlelib/pyshell.py", line 874, in __init__
    OutputWindow.__init__(self, flist, None, None)
  File "/usr/lib/python3.8/idlelib/outwin.py", line 79, in __init__
    EditorWindow.__init__(self, *args)
  File "/usr/lib/python3.8/idlelib/editor.py", line 218, in __init__
    self.set_width()
  File "/usr/lib/python3.8/idlelib/editor.py", line 366, in set_width
    self.width = pixel_width // zero_char_width
ZeroDivisionError: integer division or modulo by zero