code: def excepthook(self, except_type, exception, traceback):
      
      if except_type is DeepReferenceError:
          print(exception.msg)
      else:
          self.default_excepthook(except_type, exception, traceback)
docs: Not Used: Custom exception hook to replace sys.excepthook
  
      This is for CPython's default shell. IPython does not use sys.exepthook.
  
      https://stackoverflow.com/questions/27674602/hide-traceback-unless-a-debug-flag-is-set