29. 两数相除

import math
class Solution(object):
    def divide(self, dividend, divisor):
        """
        :type dividend: int
        :type divisor: int
        :rtype: int
        """
        self.dividend = dividend
        self.divisor = divisor
        
        a = int(operator.truediv(dividend, divisor))
        if a >= 2**31 or a < -2**31:
                return 2**31 - 1
        
        else:
                return a
        

python的除法在负数是向下取整，而本题需要向上取整

python中求幂的算法是**而不是^