import operatorsortedlist = sorted(reader, key=operator.itemgetter(3), reverse=True)
或使用lambda
sortedlist = sorted(reader, key=lambda row: row[3], reverse=True)

import operatorsortedlist = sorted(reader, key=operator.itemgetter(3), reverse=True)
或使用lambda
sortedlist = sorted(reader, key=lambda row: row[3], reverse=True)