def signal_handler(self, signum, *frame):
        try:
            reactor.callFromThread(self.callback, *self.parameters)
        except:
            print datetime.now(), 'Signal: unhandled exception in signal callback'
            print '-' * 70
            print_exc(file = stdout)
            print '-' * 70
            stdout.flush()
        if (SIG_IGN, SIG_DFL) not in self.previous_handler:
            try:
                self.previous_handler(signum, *frame)
            except:
                print datetime.now(), 'Signal: unhandled exception in signal chain'
                print '-' * 70
                print_exc(file = stdout)
                print '-' * 70
                stdout.flush()
dataset/ETHPy150Open hgascon/pulsar/pulsar/core/sippy/Signal.py/Signal.signal_handler/swapped operands of `not in`