标题：请问群主boll策略 上述写法如何控制重复开仓

if close[-1]>top[-1] and close[-2]<top[-2] :
            buy_close(context.s1, "market", volume=1*context.cca)
            buy_open(context.s1, "market", volume=1*context.cca)
            lst_signal1.append(1)
        elif close[-1]<bom[-1] and close[-2]>bom[-2] :
            portfolio = get_portfolio(context.s1,0)
            sell_close(context.s1,"market", volume=1*context.cca)
            sell_open(context.s1,"market", volume=1*context.cca)
            lst_signal1.append(0)