Python：“Nonetype”对象没有属性键

Question

   def index_dir(self, base_path): 

        num_files_indexed = 0
        allfiles = os.listdir(base_path)
        #print allfiles
        num_files_indexed = len(allfiles)
        #print num_files_indexed
        docnumber = 0
        self._inverted_index = {} #dictionary
        for file in allfiles: 
                self.documents = [base_path+file] #list of all text files
                f = open(base_path+file, 'r')
                lines = f.read()
  # Tokenize the file into words
                tokens = self.tokenize(lines)
                docnumber = docnumber + 1
                print 'docnumber', docnumber
                for term in tokens:  
# check if the key already exists in the dictionary, if yes, 
# just add a new value for the key
                    #if self._inverted_index.has_key(term)
                    if term in sorted(self._inverted_index.keys()):
                        docnumlist = self._inverted_index.get(term)
                        docnumlist = docnumlist.append(docnumber)
                    else:
# if the key doesn't exist in dictionary, add the key (term) 
# and associate the docnumber value with it. 
                        self._inverted_index = self._inverted_index.update({term: docnumber})
   #self._inverted_index[term] = docnumber 
                f.close()
        print 'dictionary', self._inverted_index 
        print 'keys', self._inverted_index.keys()
        return num_files_indexed

我正在从事一个信息检索项目，我们应该在其中爬取多个文本文件，对文件进行标记并将单词存储在倒排列表（字典）数据结构中。

例如： doc1.txt：“狗跑了” doc2.txt：“猫睡着了”
_inverted_index = { 'the': [0,1], '狗'：[0]， “跑”：[0]， '猫'：[1]， “睡觉”：[1] } 其中 0,1 是 docID

我收到以下错误： “非类型”对象没有属性键。第 95 行

非常感谢所有帮助。

Answer 1

当self._inverted_index 是字典时，self._inverted_index.update 将就地更新它并返回None（就像大多数mutators 一样）。因此，您的代码中的灾难性错误是：

 self._inverted_index = self._inverted_index.update({term: docnumber})

将self._inverted_index 设置为None。改成

 self._inverted_index.update({term: docnumber})

只需接受就地更新（突变）并且没有错误分配！