>>> def int2bin(n):
	'From positive integer to list of binary bits, msb at index 0'
	if n:
		bits = []
		while n:
			n,remainder = divmod(n, 2)
			bits.insert(0, remainder)
		return bits
	else: return [0]

	
>>> def bin2int(bits):
	'From binary bits, msb at index 0 to integer'
	i = 0
	for bit in bits:
		i = i * 2 + bit
	return i