将数组用作字典键是否属于不良编程实践？

在Python中，数组无法直接作为字典的键，但可以将数组转换为逗号分隔的字符串来充当字典键。我在LeetCode的3Sum、4Sum等问题中使用过这个方法，均能通过测试。具体步骤如下：

• 排序数组
• 将数组转换为字符串
• 存入字典
• 以O(1)的时间复杂度检查重复项

以下是用这个方法实现的3Sum完整解决方案：

class Solution(object):
    def threeSum(self, nums):
        finreturn = []
        count_dict = {}
        # 统计每个数字的出现次数
        for num in nums:
            if num in count_dict:
                count_dict[num] += 1
            else:
                count_dict[num] = 1
        comparedict = {}
        for key1 in count_dict:
            for key2 in count_dict:
                target = -(key1 + key2)
                if target in count_dict:
                    # 临时减少计数，避免重复使用同一元素
                    count_dict[key1] -= 1
                    count_dict[key2] -= 1
                    count_dict[target] -= 1
                    # 生成三元组并排序
                    temp_list = [key1, key2, target]
                    temp_list.sort()
                    # 转换为字符串作为去重判断的键
                    compare_key = f"{temp_list[0]},{temp_list[1]},{temp_list[2]}"
                    # 检查计数合法且该三元组未被记录过
                    if count_dict[key1] >= 0 and count_dict[key2] >= 0 and count_dict[target] >= 0 and compare_key not in comparedict:
                        finreturn.append(temp_list)
                        comparedict[compare_key] = 1
                    # 恢复计数，不影响后续循环
                    count_dict[key1] += 1
                    count_dict[key2] += 1
                    count_dict[target] += 1
        return finreturn

内容的提问来源于stack exchange，提问作者Matthew Setiawan