https://quantiacs.com/documentation/en/examples/q18_quick_start.html

def load_data(period):
    futures = qndata.futures.load_data(tail=period, assets=["F_DX"]).isel(asset=0)
    stocks  = qndata.stocks.load_spx_data(tail=period)
    return {"futures": futures, "stocks": stocks}, futures.time.values



qnbt.backtest(
    competition_type= "stocks_s&p500",
    load_data= load_data,
    lookback_period= 365,
    start_date= "2006-01-01",
    strategy= strategy,
    window= window
)

Error happened in validate_data function

File ~/book/qnt/backtester.py:386, in backtest.<locals>.validate_data(data)
    377 def validate_data(data):
    378     mismatches = {
    379         'stocks': ['stocks', 'stocks_long'],
    380         'stocks_s&p500': ['stocks_s&p500'],
   (...)
    384         'futures': ['futures']
    385     }
--> 386     if data.name not in mismatches.get(competition_type, []):
    387         log_err(
    388             f"WARNING! The data type and the competition type are mismatched. Data type: {data.name}, competition type: {competition_type}")

AttributeError: 'tuple' object has no attribute 'name'