Product of Array Except Self

Given an array nums of n integers where n > 1, return an array output such that output[i] is equal to the product of all the elements of nums except nums[i].

Example:

Input: [1,2,3,4]
Output: [24,12,8,6]
Constraint: It’s guaranteed that the product of the elements of any prefix or suffix of the array (including the whole array) fits in a 32 bit integer.

Note: Please solve it without division and in O(n).

Follow up:
Could you solve it with constant space complexity? (The output array does not count as extra space for the purpose of space complexity analysis.)

class Solution(object):
    def productExceptSelf(self, nums):
        """
        :type nums: List[int]
        :rtype: List[int]
        """
        re = [1 for _ in range(len(nums))]
        forward = [1 for _ in range(len(nums))]
        backwrad = [1 for _ in range(len(nums))]
        forward[0] = 1
        backward[len(nums)-1] = 1
        for i in range(1,len(nums)):
            forward[i] = forward[i-1] * nums[i-1]
        for i in range(len(nums)-2,-1,-1):
            backward[i] = backward[i+1] * nums[i+1]
        for i in range(0,len(nums)):
            re[i] = forward[i] * backward[i]
        return re

Product of Array Except Self