Sanity testing on loaded data in BT.

[Sumit Pandey]

Hello,
I am currently writing a script to load multiple securities data and perform operations on them. Since I am loading the CSV data into BT, I wish to see all the data which is loaded, to make sure BT is correctly reading what I am passing it. Is there any way to do this.
The reason arised because of implementation of one of the strategy, https://teddykoker.com/2019/05/momentum-strategy-from-stocks-on-the-move-in-python/
where I am passing cnx 200 stocks data.

for ticker in tickers:
    data =  bt.feeds.GenericCSVData(dataname=f"G:\\{ticker}.csv",
                            nullvalue=0.0,dtformat=('%d-%m-%Y'),
                            fromdate=datetime(2015, 1, 1),
                            todate=datetime(2020, 7, 31),
                            datetime=0,open=1,high=2,low=3,close=4,volume=5,openinterest=-1
                            )
    cerebro.adddata(data)

and defining a momentum strategy where regression slope will be calculated on rolling 90 dataclose.

class Momentum(bt.Indicator):
    lines = ('trend',)
    params = (('period', 90),)

    #def __init__(self):
        #self.addminperiod(self.params.period)

    def next(self):
        returns = np.log(self.data.get(size=self.p.period))
        x = np.arange(len(returns))
        #mask = ~np.isnan(x) & ~np.isnan(returns)
        slope, _, rvalue, _, _ = linregress(x, returns)
        annualized = (1 + slope) ** 252
        self.lines.trend[0] = annualized * (rvalue ** 2)

The error which is being thrown is : ValueError: Inputs must not be empty.
I need to know whether the data stored in cerebro is correct.

[ab_trader]

Is there any way to do this.

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