class PEUniverseSelection(QCAlgorithm):
    
    filteredByPrice = None
    
    def Initialize(self):
        self.SetStartDate(2019, 7, 1)  
        self.SetEndDate(2020, 7, 1) 
        self.SetCash(100000)  
        self.AddUniverse(self.CoarseSelectionFilter, self.FineSelectionFilter)
        self.UniverseSettings.Resolution = Resolution.Hour 
        self.SetSecurityInitializer(lambda x: x.SetDataNormalizationMode(DataNormalizationMode.Raw))
        self.__numberOfSymbols = 300
        self.__numberOfSymbolsFine = 5

    def CoarseSelectionFilter(self, coarse):
        sortedByDollarVolume = sorted(coarse, key=lambda x: x.DollarVolume, reverse=True)
        
        filteredByPrice = [x.Symbol for x in sortedByDollarVolume if x.Price > 10]
        
        return filteredByPrice[:self.__numberOfSymbols]
        
    def FineSelectionFilter(self, fine):
         # sort descending by P/E ratio
        sortedByPeRatio = sorted(fine, key=lambda x: x.ValuationRatios.PERatio, reverse=True)
    
        # take the top entries from our sorted collection
        return [ x.Symbol for x in sortedByPeRatio[:self.__numberOfSymbolsFine] ]
   
    def OnSecuritiesChanged(self, changes):
        self.changes = changes
        self.Log(f"OnSecuritiesChanged({self.UtcTime}):: {changes}")
        
        #1. Liquidate removed securities
        for security in changes.RemovedSecurities:
         if security.Invested:
                self.Liquidate(security.Symbol)
    
        #2. We want 10% allocation in each security in our universe
        for security in changes.AddedSecurities:
            self.SetHoldings(security.Symbol, 0.1)