code: def die (fmt, *args):
      
      if not len (args):
          raise SystemExit ('error: ' + text_type (fmt))
      raise SystemExit ('error: ' + (fmt % args))
docs: Raise a :exc:`SystemExit` exception with a formatted error message.
  
      :arg str fmt: a format string
      :arg args: arguments to the format string
  
      If *args* is empty, a :exc:`SystemExit` exception is raised with the
      argument ``'error: ' + str (fmt)``. Otherwise, the string component is
      ``fmt % args``. If uncaught, the interpreter exits with an error code and
      prints the exception argument.
  
      Example::
  
         if ndim != 3:
            die ('require exactly 3 dimensions, not %d', ndim)