"""
Matt Laporte <lapo3399@gmail.com> 2008
---
Base conversion tools. Allows for A-Z notation for digits greater than 9.
"""
from types import StringType
 
def inBase(num, base, fromBase = 10, result = ''):
	""" 
	Converts any number in fromBase to its representation in base.
	Defaults to converting to base_num from base_10.
	"""
	if result == '': 
		#First call checks and corrections.
                if num == 0: return '0' 
		base = __check(base)
		if fromBase != 10: 
			fromBase = __check(fromBase)
			""" In order to maintain the simplicity of the actual
			conversion, this converts the number to base_10. """
			num = toBase10(num, fromBase)
			fromBase = 10
		if num < 0: 
			#Further simplification for the conversion component.
			result = '-' + result
			num = -1 * num
	if num == 0: return result #Return the final result when num has been handled.
	else:
		#Conversion. This builds up result and eats away at num.
		thisDigit = num%base
		if thisDigit > 9: thisDigit = chr(thisDigit + 55) #Accounting for A-Z digits.
		else: thisDigit = str(thisDigit)
		return inBase(num/base, base, fromBase, thisDigit + result)
 
def __check(base):
	""" 
	Verifies that a given base is 2-9 or A-Z.
	Converts any base from A-Z to 10-35 for numerical calculations.
	Should be used in the form: base == __check(base).
	"""
	if type(base) == StringType and ((ord(base) > 96) and (ord(base) < 123)):
		#Correct a-z to A-Z
		base = chr(ord(base)-32)
	if type(base) == StringType and ((ord(base) > 64) and (ord(base) < 91)):
		#Correct A-Z to 10-35
		return (ord(base) - 55)
	elif type(base) != type(1) or type(base) == StringType:
		#Not an integer, or any string other than A-Z.
		raise TypeError, 'invalid base type for inBase()'
	if base <= 1 or base > 36:
		raise ValueError, 'invalid base for inBase(): %s' % base
	return base
 
def toBase10(num, base):
	""" 
	Converts any number represented in base to its base_10 representation.
	"""
	sum = 0
	parseNum = str(num)
	indices = range(len(parseNum)) #Exponents depend on digit place, indices necessary.
	for i in indices:
		#Add the decimal representations of the digits.
		sum += int(parseNum[i])*base**int(indices[::-1][i])
	return sum

>>> int(0xAF)
175
>>> int('101',2)
5
>>> int('0xaf3', 16)
2803
>>>

import string
 
def convDecToBase(num, base, dd=False):
    if not 2 <= base <= 36:
        raise ValueError, 'The base number must be between 2 and 36.'
    if not dd:
        dd = dict(zip(range(36), list(string.digits+string.ascii_lowercase)))
    if num == 0: return ''
    num, rem = divmod(num, base)
    return convDecToBase(num, base, dd)+dd[rem]