## Example 7:  Format an RGB value (three 1-byte numbers) as a 6-digit hexadecimal string.
print "%02X%02X%02X" % (255, 0, 128)
def toHex(i):
    def _toHex(i):
        if i <= 15:
            if i <=9:
                return str(i)
            return chr(ord("A") + (i-10))
        return _toHex(i >> 4) + _toHex(i%16)
    res = _toHex(i)
    if len(res) == 1:
        res = "0" + res
    return res
print "".join((toHex(255), toHex(0), toHex(128)))