Convert a decimal to a given base and then back to it's decimal representation.

convert.py

# convert a decimal to a given base
def d2b(dec, base):
    stack = []
    result = ''
    while dec > 0:
        rem = dec % base
        dec = dec / base
        stack.append(rem)
    while stack:
        result += str(stack.pop())
    print result

# convert the number back to its decimal representation
def b2d(num, base):    
    result = 0 
    for n in str(num):
        result *= base
        result += int(n)
    print result

d2b(10,16)
b2d(101010101010101010,2)