Hello, when I launch this algorithm it returns me an error.However I don't see what can be wrong.Can Someone help me please


Thank You 

class DynamicHorizontalChamber(QCAlgorithm): def Initialize(self): self.SetStartDate(2019, 1, 7) self.SetEndDate(2019, 4, 1) self.SetCash(100000) self.UniverseSettings.Resolution = Resolution.Daily self.AddUniverse(self.CoarseSelectionFunction) self.averages = { } def SelectionFunction(self, universe): selected = [] universe = sorted(universe, key=lambda c: c.DollarVolume, reverse=True) universe = [c for c in universe if c.Price > 100][:100] for coarse in universe: symbol = coarse.Symbol if symbol not in self.averages: history = self.History(symbol, 200, Resolution.Daily) self.averages[symbol] = Selection(history) self.averages[symbol].update(self.Time, coarse.AdjustedPrice) if self.averages[symbol].is_ready() and self.averages[symbol].stt < 20: selected.append(symbol) return selected[100:] def OnSecuritiesChanged(self, changes): self.changes = changes self.Log(f"OnSecuritiesChanged({self.Time}):: {changes}") for security in self.changes.RemovedSecurities: if security.Invested: self.Liquidate(security.Symbol) for security in self.changes.AddedSecurities: self.SetHoldings(security.Symbol, 0.10) class Selection(): def __init__(self,history): self.stt = StandardDeviation(200) for bar in history.itertuples(): self.stt.Update(bar.Index[1],bar.close) def is_ready(self): return self.stt.IsReady def update(self, time, price): self.stt.Update(time,price)