numList = [2000, 2003, 2005, 2006]
stringList = ["A", "B", "C"]
mixedList = [1, 2, "three", 4]
subList = ["Python", "Phrasebook", ["Copyright",2006]]
listList = [numList, stringList, mixedList, subList]
if isinstance(subList, list):
print subList[2][0]