405. Convert a Number to Hexadecimal

class Solution:
    def toHex(self, num):
        """
        :type num: int
        :rtype: str
        """
        digits = "0123456789abcdef"
        temp = ""
        number = num
        if number == 0:
            return "0"
        elif number < 0:
            number += 0x100000000
        while number >0:
            remain = number % 16
            number = number //16
            temp += digits[remain]
        return temp[::-1]