numList = [2000, 2003, 2005, 2006]
stringList = ["Essential", "Python", "Code"]
mixedList = [1, 2, "three", 4]
subList = ["A", "B", ["C", 2006]]
listList = [numList, stringList, mixedList, subList]
for x in listList:
for y in x:
if isinstance(y, int):
print y + 1
if isinstance(y, basestring):
print "String:" + y