def get_index_list(index_symbol = 'sh000068'):
    stocks2 = []
    stocks = ak.index_stock_hist(index_symbol).stock_code
    for stock in stocks[:]:
        if int(stock) < 100000:
            stock = 'sz' + stock
        else:
            stock = 'sh' + stock
        stocks2.append(stock)
    return stocks2
stock_pool = get_index_list()