Single Number Python Solution with Tests

lcpy gen -n 136   # by problem number
lcpy gen -s single_number   # by problem name

Input: nums = [2,2,1]
Output: 1

Input: nums = [4,1,2,1,2]
Output: 4

Input: nums = [1]
Output: 1

from functools import reduce
from operator import xor


class Solution:
    # Time: O(n)
    # Space: O(1)
    def single_number(self, nums: list[int]) -> int:
        return reduce(xor, nums)