Product of Array Except Self — Python

# Time:  O(n)
# Space: O(1)

class Solution(object):
    # @param {integer[]} nums
    # @return {integer[]}
    def productExceptSelf(self, nums):
        if not nums:
            return []

        left_product = [1 for _ in xrange(len(nums))]
        for i in xrange(1, len(nums)):
            left_product[i] = left_product[i - 1] * nums[i - 1]

        right_product = 1
        for i in xrange(len(nums) - 2, -1, -1):
            right_product *= nums[i + 1]
            left_product[i] = left_product[i] * right_product

        return left_product