Array - 136. Single Number

#===================================
# Tanzila Islam
# Email: tanzilamohita@gmail.com
# Language: Python 3
#===================================

class Solution:
    def singleNumber(self, nums: List[int]) -> int:
        if len(nums) == 1:
            return (nums[0])
        elif len(nums) != 0:
            res = 0
            for i in range(len(nums)):
                res ^= nums[i] 
        return res