def instantiateShootErrback():
 d = defer.Deferred()
 try:
  (1 / 0)
 except:
  d.errback()
 d.addErrback((lambda x: None))

def instantiateShootErrback ( ) : d = defer . Deferred ( ) try : ( 1 / 0 ) except : d . errback ( ) d . addErrback ( ( lambda x : None ) )
create a deferred and give it an exception result .