Function convert_interactions_amazon23

data/amazon23_data_process.py:221–262

Convert interactions to amazon18-style: - user2index - item2index - user2items[user_index] = [item_index...] - interactions list of (user_id, asin, rating, timestamp)

(reviews)

    return new_reviews, user_counts, item_counts

def convert_interactions_amazon23(reviews):
    """
    Convert interactions to amazon18-style:
    - user2index
    - item2index
    - user2items[user_index] = [item_index...]
    - interactions list of (user_id, asin, rating, timestamp)
    """

    user_reviews = collections.defaultdict(list)

    for r in reviews:
        user_reviews[r["user_id"]].append(r)

    # Sort each user's reviews by time
    for u in user_reviews:
        user_reviews[u].sort(key=lambda x: x["timestamp"])

    user2index, item2index = {}, {}
    user2items = collections.defaultdict(list)
    interactions = []

    for user in user_reviews:
        if user not in user2index:
            user2index[user] = len(user2index)

        for r in user_reviews[user]:
            item = r["asin"]
            if item not in item2index:
                item2index[item] = len(item2index)

            uid = user2index[user]
            iid = item2index[item]

            user2items[uid].append(iid)
            interactions.append((user, item, r["rating"], r["timestamp"]))

    print(
        f"[Mapping] Users={len(user2index)}, Items={len(item2index)}, "
        f"Interactions={len(interactions)}"
    )
    return user2items, user2index, item2index, interactions


def build_interaction_list_amazon23(reviews, user2index, item2index, asin2title):