def blastoff(num):
    while num>0:
        print num
        num-=1  # num=num-1
    print "done"

def blastoff2(num):
    for i in range(num):
        print num-i
    print "done"

def blastoff3(num):
    #avoid loop
    if num==0:
        print "done"
        return
    print num
    blastoff3(num-1)
def listManipulation():
    list1=[4,5,6,7,8]
    list2=[5,6,7]
    print "List1 is:",list1
    print "List2 is:",list2
    print "Every other number in list1:",list1[::2]
    list1[3]=73
    print "4th element changed:",list1
    for i in range(len(list1)):
        list1[i]+=2 #list[item]= list[item] + 2
    print "Increment by 2:",list1
def stringManipulation():
    mystring="HELLO"
    newstring=mystring[0:2]+"A"+mystring[3::]
    print mystring
    print newstring