Mine

        self.tmpext = self.romext[index].split(';')
        for rom in os.listdir(self.rompath[index]):
            for ext in self.tmpext:
                if ext.count(rom[-3].lower()) > 0: ## Checks if last three characters are in the romext list
                    self.extlist.append(rom[-4])        ## Adds rom extension to list, along with dot(.)
                    self.lstEmu.addItem(xbmcgui.ListItem(str(rom[0:-4]), index, "", ""))
                #
            #
        self.lblCount.setLabel(str(len(self.extlist))+' '+LANGUAGE[XBMC_LANGUAGE][9])