def is_lower_limit(self, symbol):
    '是否跌停'
    tick = self.tick_dict.get(symbol, None)
    if ((tick is None) or (tick.limit_down is None) or (tick.limit_down == 0)):
        return False
    if (tick.ask_price_1 == tick.limit_down):
        return True
是否跌停
def is_lower_limit(self, symbol):
    
    tick = self.tick_dict.get(symbol, None)
    if ((tick is None) or (tick.limit_down is None) or (tick.limit_down == 0)):
        return False
    if (tick.ask_price_1 == tick.limit_down):
        return True