(cls, seq)
return [], new_seq, None
Return seq so that none of the elements are of type `cls`. This is
        the vanilla routine that will be used if a class derived from AssocOp
        does not define its own flatten routine.
Return seq so that none of the elements are of type `cls`. This is
        the vanilla routine that will be used if a class derived from AssocOp
        does not define its own flatten routine.
Return seq so that none of the elements are of type cls . This is the vanilla routine that will be used if a class derived from AssocOp does not define its own flatten routine .
def flatten(cls, seq):
        """Return seq so that none of the elements are of type `cls`. This is
        the vanilla routine that will be used if a class derived from AssocOp
        does not define its own flatten routine."""
        # apply associativity, no commutativity property is used
        new_seq = []
        while seq:
            o = seq.pop()
            if o.__class__ is cls:  # classes must match exactly
                seq.extend(o.args)
            else:
                new_seq.append(o)
        # c_part, nc_part, order_symbols
        return [], new_seq, None
def flatten ( cls , seq ) : # apply associativity, no commutativity property is used new_seq = [ ] while seq : o = seq . pop ( ) if o . __class__ is cls : # classes must match exactly seq . extend ( o . args ) else : new_seq . append ( o ) # c_part, nc_part, order_symbols return [ ] , new_seq , None