How to use the hikyuu.Datetime function in hikyuu

high = mid - 1
                
        if mid >= total:
            return (0, 0)
            
            
        start_pos = mid
        low = mid
        high = total - 1
        while low <= high:
            tmp_datetime = Datetime(data.index[high])
            if end_datetime > tmp_datetime:
                mid = high + 1
                break
            
            tmp_datetime = Datetime(data.index[low])
            if tmp_datetime >= end_datetime:
                mid = low
                break
            
            mid = (low + high) // 2
            tmp_datetime = Datetime(data.index[mid])
            if end_datetime > tmp_datetime:
                low = mid + 1
            else:
                high = mid - 1
                
        end_pos = total if mid >= total else mid
        if start_pos >= end_pos:
            return (0,0)
        
        return (start_pos, end_pos)

:param int end_ix: 结束位置
        :param KRecordListPtr out_buffer: 传入的数据缓存，读取数据后使用 
                                           out_buffer.append(krecord) 加入数据        
        """
        if start_ix >= end_ix or start_ix <0 or end_ix <0:
            return
        
        data = self._get_bars(market, code, ktype)
                    
        if len(data) < start_ix:
            return
        
        total = end_ix if end_ix < len(data) else len(data)
        for i in range(start_ix, total):
            record = KRecord()
            record.datetime = Datetime(data[i].get('datetime'))
            record.openPrice = data[i].get('open')
            record.highPrice = data[i].get('high')
            record.lowPrice = data[i].get('low')
            record.closePrice = data[i].get('close')
            record.transAmount = data[i].get('amount')
            record.transCount = data[i].get('vol')
            out_buffer.append(record)

"""转化为numpy结构数组"""
        t_type = np.dtype({'names':['证券代码', '证券名称', '买入日期', 
                                    '已持仓天数', '持仓数量', '投入金额', 
                                    '当前市值', '盈亏金额', '盈亏比例'], 
                'formats':['U10','U20', 'datetime64[D]', 'i', 'i', 'd',
                           'd', 'd', 'd']})
        
        sm = StockManager.instance()
        query = Query(-1)
        data = []
        for pos in pos_list:
            invest = pos.buyMoney - pos.sellMoney + pos.totalCost
            k = pos.stock.getKData(query)
            cur_val = k[0].closePrice * pos.number
            bonus = cur_val - invest
            date_list = sm.getTradingCalendar(QueryByDate(Datetime(pos.takeDatetime.date())))
            data.append((pos.stock.market_code, pos.stock.name, 
                         pos.takeDatetime, len(date_list), pos.number, 
                         invest, cur_val, bonus,
                         100 * bonus / invest))
        
        return np.array(data, dtype=t_type)

:param str market: 市场标识
        :param str code: 证券代码
        :param int pos: 指定位置（大于等于0）
        :param KQuery.KType ktype: K线类型        
        """
        record = KRecord()
        if pos < 0:
            return record
        
        data = self._get_bars(market, code, ktype)
        if data is None:
            return record
        
        if pos < len(data):
            record.datetime = Datetime(data[pos].get('datetime'))
            record.openPrice = data[pos].get('open')
            record.highPrice = data[pos].get('high')
            record.lowPrice = data[pos].get('low')
            record.closePrice = data[pos].get('close')
            record.transAmount = data[pos].get('amount')
            record.transCount = data[pos].get('vol')
            
        return record

def indicator_getitem(data, i):
    """
    :param i: int | Datetime | slice | str 类型
    """
    if isinstance(i, int):
        length = len(data)
        index = length + i if i < 0 else i
        if index < 0 or index >= length:
            raise IndexError("index out of range: %d" % i)
        return data.get(index)
    
    elif isinstance(i, slice):
        return [data.get(x) for x in range(*i.indices(len(data)))]

    elif isinstance(i, Datetime):
        return data.getByDate(i)

    elif isinstance(i, str):
        return data.getByDate(Datetime(i))

    else:
        raise IndexError("Error index type")

"""
    if isinstance(i, int):
        length = len(data)
        index = length + i if i < 0 else i
        if index < 0 or index >= length:
            raise IndexError("index out of range: %d" % i)
        return data.get(index)
    
    elif isinstance(i, slice):
        return [data.get(x) for x in range(*i.indices(len(data)))]

    elif isinstance(i, Datetime):
        return data.getByDate(i)

    elif isinstance(i, str):
        return data.getByDate(Datetime(i))

    else:
        raise IndexError("Error index type")

:param int end_ix: 结束位置
        :param KRecordListPtr out_buffer: 传入的数据缓存，读取数据后使用 
                                           out_buffer.append(krecord) 加入数据        
        """
        if start_ix >= end_ix or start_ix <0 or end_ix <0:
            return
        
        data = self._get_bars(market, code, ktype)
                    
        if len(data) < start_ix:
            return
        
        total = end_ix if end_ix < len(data) else len(data)
        for i in range(start_ix, total):
            record = KRecord()
            record.datetime = Datetime(data[i].get('datetime'))
            record.openPrice = data[i].get('open')
            record.highPrice = data[i].get('high')
            record.lowPrice = data[i].get('low')
            record.closePrice = data[i].get('close')
            record.transAmount = data[i].get('amount')
            record.transCount = data[i].get('vol')
            out_buffer.append(record)