code: def print_stack(f=None, limit=None, file=None):
      
      if f is None:
          try:
              raise ZeroDivisionError
          except ZeroDivisionError:
              f = sys.exc_info()[2].tb_frame.f_back
      print_list(extract_stack(f, limit), file)
docs: Print a stack trace from its invocation point.
  
      The optional 'f' argument can be used to specify an alternate
      stack frame at which to start. The optional 'limit' and 'file'
      arguments have the same meaning as for print_exception().