OffLineRec/calI2I.py

#coding utf-8
import sys
from operator import itemgetter
import json

if __name__=="__main__":
    #1.load data
    nowdate=sys.argv[1]
    f = open("./data/user_item_share_"+nowdate)
    user_item_dict={}
    item_dict = {}  
    while True:
        line = f.readline()
        if not line:
            break
        items = line.strip().split("\t")
        if len(items)<3:
            continue
        key = (items[1],items[2])
        #print(key)
        if key not in user_item_dict:
            user_item_dict[key] = 1
        else:
            user_item_dict[key] = user_item_dict[key]+1
        if items[2] not in item_dict:
            item_dict[items[2]] = 1
        else:
            item_dict[items[2]] = item_dict[items[2]]+1
    f.close()
    #((user,item), score)
    #print(user_item_dict)
    #2. (uid, [(vid, score)....])
    user_group_dict = {}
    for k, v in user_item_dict.items():
        uid = k[0]
        vid = k[1]
        score = v
        vid_list = []
        if uid not in user_group_dict:
            vid_list.append((vid, score))
            user_group_dict[uid] = vid_list
        else:
            vid_list = user_group_dict[uid]
            vid_list.append((vid, score))
            user_group_dict[uid] = vid_list
    #print(user_group_dict)
    item_pair_dict = {}
    #3. expand item
    for k, v_list in user_group_dict.items():
         v_n = len(v_list)
         if v_n<2:
             continue
         for i in range(v_n):
             for j in range(1, v_n):
                if v_list[i][0] == v_list[j][0]:
                    continue
                item_key = (v_list[i][0], v_list[j][0])
                item_score = min(v_list[i][1], v_list[j][1])
                if item_key not in item_pair_dict:
                    item_pair_dict[item_key] = item_score
                else:
                    item_pair_dict[item_key] = item_pair_dict[item_key]+item_score
    #print(item_pair_dict)
    print(len(item_pair_dict))
    print(len(item_dict))
    left_pair_num = 0
    rec_item_dict = {}
    #4. rec item
    for k, v in item_pair_dict.items():
        if v<2:
            continue
        left_pair_num+=1
        item1 = k[0]
        item2 = k[1]
        pair_score = v
        if item1 in item_dict:
             item_score1 = item_dict[item1]
             i2i_pro = pair_score/(item_score1+5)
             rec_list1 = []
             if item2 not in rec_item_dict:
                 rec_list1.append((item1, i2i_pro, pair_score, item_score1))
                 rec_item_dict[item2] = rec_list1
             else:
                 rec_list1 = rec_item_dict[item2]
                 rec_list1.append((item1, i2i_pro, pair_score, item_score1))
                 rec_item_dict[item2] = rec_list1
        if item2 in item_dict:
             item_score2 = item_dict[item2]
             i2i_pro = pair_score/(item_score2+5)
             rec_list2 = []
             if item1 not in rec_item_dict:
                 rec_list2.append((item2, i2i_pro, pair_score, item_score2))
                 rec_item_dict[item1] = rec_list2
             else:
                 rec_list2 = rec_item_dict[item1]
                 rec_list2.append((item2, i2i_pro, pair_score, item_score2))
                 rec_item_dict[item1] = rec_list2          
     
    #(item, share_count)
    print(left_pair_num)
    #print(rec_item_dict)
    final_rec_list = []
    #f = open("rec_result", "w")
    #5. sorted item_list
    
    for k,v in rec_item_dict.items():
        v_set = set('')
        value_list = v
        dup_list = []
        for item in value_list:
            if item[0] in v_set:
                continue
            v_set.add(item[0])
            dup_list.append(item)
        sorted_v = sorted(dup_list, key=itemgetter(1), reverse=True)
        final_rec_list.append((k, sorted_v))
    #print(final_rec_list[:1])
    #json_str = json.dumps(final_rec_list)
    with open("./data/rec_result_"+nowdate+".json", "w") as f :
        json.dump(final_rec_list, f)