def factorial(n):
    """Returns the factorial of n, i.e., 1*2*3*...*(n-1)*n."""
    result = 1
    for i in range(1,n+1):
        result = result*i
    return result

# fact(n) = { 1             if n=0 }
#           { n*fact(n-1)   otherwise }

def fact(n):
    """Returns the factorial of n, i.e., 1*2*3*...*(n-1)*n."""
    print "n=",n
    if n==0:
        result = 1
    else:
        result = n*fact(n-1)
    print "result=",result
    return result




aList = [4,78,1,3]

def sumOfList(aList):
    sum = 0
    for n in aList:
        sum += n
    return sum

# aList = [4,78,1,3]
# aList[1:] = [78,1,3]
# aList[0] = 4


def sumList(aList):
    if aList == []:
        return 0
    else:
        return aList[0]+sumList(aList[1:])