def print_tracebacks(self, excid=None):
        if excid is None:
            for (en,ev,etb,ei) in self.elist:
                print (self._get_engine_str(ei))
                print (etb or 'No traceback available')
                print ()
        else:
            try:
                en,ev,etb,ei = self.elist[excid]
            except:
                raise IndexError(excid%"an exception with index %i does not exist")
            else:
                print (self._get_engine_str(ei))
                print (etb or 'No traceback available')
dataset/ETHPy150Open ipython/ipython-py3k/IPython/parallel/error.py/CompositeError.print_tracebacks/swapped operands of `%`