def calc_recursion(number, res = 0):
    if not number: return res
    else: return calc_recursion(number // 10, res + number % 10)

def map_int(n):
    return sum(map(int, str(n)))

def map_ord(n):
    s = str(n)
    return sum(map(ord, s)) - len(s)*ord('0')

def calc_numbers1(number):
    res = 0
    divisor = 1
    while divisor < number:
        res += (number % (divisor*10)) // (divisor)
        divisor *= 10
    return res

def calc_numbers2(number):
    res = 0
    while number:
        res += number % 10
        number //= 10
    return res


for f in map_int,map_ord,calc_numbers1,calc_numbers2:
    n = 123456789
    start = time()
    for i in range(100000):
        s = f(n)
    print( "time spent for {0} = {1} sec".format( f.__name__, time() - start ))

n=list(range(10))
print sum(map(int, str(n))),

>>> xrange
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'xrange' is not defined
>>> range(10)
range(0, 10)
>>>