code: def get_font_info(font_name, subst_ok=True):
      
      global font_dir
      if font_name in font_dir:
          font_info = font_dir[font_name]
      elif subst_ok:
          # substitute an alternate font
          font_name = resolve_alias('fixed', 'fixed')
          font_info = font_dir[font_name]
      else:
          raise KeyError(font_name)
  
      return font_info
docs: Return known info on an externally loadable font (including its path).
      `font_name` is assumed to have already been resolved from an alias.
      Will return a KeyError in the case of a missing font, unless
      subst_ok is True, in which case an alternate font may be returned.