apriori算法的代码

以下是一个简单的 Python 实现 apriori 算法的代码：

def apriori(transactions, min_support):
    itemsets = {}
    for transaction in transactions:
        for item in transaction:
            if item not in itemsets:
                itemsets[item] = 0
            itemsets[item] += 1

    itemsets = {frozenset([item]): support for item, support in itemsets.items() if support >= min_support}
    while itemsets:
        yield itemsets
        itemsets = join(itemsets)
        itemsets = {itemset: support for itemset, support in itemsets.items() if support >= min_support}

def join(itemsets):
    joined_itemsets = {}
    for itemset1, support1 in itemsets.items():
        for itemset2, support2 in itemsets.items():
            if len(itemset1.union(itemset2)) == len(itemset1) + 1:
                joined_itemset = itemset1.union(itemset2)
                if joined_itemset not in joined_itemsets:
                    joined_itemsets[joined_itemset] = 0
                joined_itemsets[joined_itemset] += 1
    return joined_itemsets

这个代码实现了一个简单的 apriori 算法，它接受一个交易列表和一个最小支持度，然后返回所有满足最小支持度的频繁项集。