def findItemPairs(user_id,items_with_rating):
    for item1,item2 in combinations(items_with_rating,2):
        return (item1[0],item2[0]),(item1[1],item2[1])
For each user, find all item-item pairs combos. (i.e. items with the same user)
dataset/ETHPy150Open evancasey/spark-knn-recommender/algorithms/itemSimilarity.py/findItemPairs