code: def reset():
      
      global _handlers, python_signal
      for sig, (previous, _) in _handlers.iteritems():
          if not previous:
              previous = SIG_DFL
          python_signal.signal(sig, previous)
      _handlers = dict()
docs: Clear global data and remove the handlers.
      CAUSION! This method sets as a signal handlers the ones which it has
      noticed on initialization time. If there has been another handler installed
      on top of us it will get removed by this method call.