【leetcode 简单】第三十三题 只出现一次的数字

def make():
    fil = {}
    def filter_nums(nums):
        for i in nums:
            if i not in fil:
                fil[i] =0
            else:
                fil[i] +=1
        return [i[0] for i in fil.items() if i[1] == 0][0]
    return filter_nums

class Solution:
    def singleNumber(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        a=make()
        return a(nums)