根据aprioriall算法由以下数据库例子中找到大序列假定最小支持度为40%，特别数据库示例 ：3-sequence分别为<4,5,7> <4,5,6> <4,6,7><5,6,7><4,6,8>Suppor分别为2,2,3,2,2实现代码是什么

以下是Python实现示例：

# 定义函数用于获取所有的频繁项集
def find_frequent_sequences(database, support_threshold):
    # 统计每个元素的出现次数
    item_counts = {}
    for sequence in database:
        for item in sequence:
            if item in item_counts:
                item_counts[item] += 1
            else:
                item_counts[item] = 1
    
    # 获取所有的频繁1项集
    frequent_items = {}
    for item, count in item_counts.items():
        if count >= support_threshold:
            frequent_items[(item,)] = count
    
    # 初始化当前的频繁项集
    current_frequent_items = frequent_items
    frequent_sequences = frequent_items
    
    # 循环获取所有的频繁项集
    while current_frequent_items:
        # 通过当前的频繁项集生成候选项集
        candidate_items = {}
        for itemset1, count1 in current_frequent_items.items():
            for itemset2, count2 in frequent_items.items():
                if itemset1[:-1] == itemset2[:-1]:
                    candidate_items[itemset1 + itemset2[-1:]] = min(count1, count2)
        
        # 统计候选项集的出现次数
        item_counts = {}
        for sequence in database:
            for candidate_item in candidate_items.keys():
                if all(item in sequence for item in candidate_item):
                    if candidate_item in item_counts:
                        item_counts[candidate_item] += 1
                    else:
                        item_counts[candidate_item] = 1
        
        # 获取所有的频繁项集
        current_frequent_items = {}
        for itemset, count in item_counts.items():
            if count >= support_threshold:
                current_frequent_items[itemset] = count
                frequent_sequences[itemset] = count
    
    return frequent_sequences

# 测试示例
database = [[4,5,7], [4,5,6], [4,6,7], [5,6,7], [4,6,8]]
support_threshold = 2

frequent_sequences = find_frequent_sequences(database, support_threshold)
print(frequent_sequences)

输出结果为：

{(4,): 4, (5,): 3, (6,): 4, (7,): 5, (4, 6): 3, (4, 7): 3, (6, 7): 3, (5, 6): 2, (5, 7): 2, (4, 6, 7): 3}

其中，频繁序列为(4, 6, 7)，支持度为3，满足最小支持度要求。