程式碼如下：

#encoding:utf-8

fin = open('1.txt', 'r')

'''
建立正向索引:
 “文件1”的ID > 單詞1：出現位置列表；單詞2：出現位置列表；…………
 “文件2”的ID > 此文件出現的關鍵詞列表。
'''
forward_index = {}
for line in fin:
    line = line.strip().split()
    forward_index[int(line[0])] = {}
    words = line[1].split(',')
    for i, index in enumerate(words):
        if
 
 int(index) not in forward_index[int(line[0])].keys():
            forward_index[int(line[0])][int(index)] = [i]
        else:
            forward_index[int(line[0])][int(index)].append(i)
print 'forward_index:', forward_index

'''
建立倒排索引：
 “關鍵詞1”：“文件1”的ID，“文件2”的ID，…………
 “關鍵詞2”：帶有此關鍵詞的文件ID列表。
'''
inverted_index = {}
for
 
 doc_id, words in forward_index.items():
    for word_id in words.keys():
        if word_id not in inverted_index.keys():
            inverted_index[word_id] = [doc_id]
        elif doc_id not in inverted_index[word_id]:
            inverted_index[word_id].append(doc_id)
print 'inverted_index:', inverted_index
 

輸入（文件id：單詞id）：
1 3,4
2 3,4,2,4
3 2

輸出：
forward_index: {1: {3: [0], 4: [1]}, 2: {2: [2], 3: [0], 4: [1, 3]}, 3: {2: [0]}}
inverted_index: {2: [2, 3], 3: [1, 2], 4: [1, 2]}