Python:'Nonetype'对象没有属性键

时间:2010-09-12 06:05:20

标签: python

   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

我正在开展一个信息检索项目,我们应该抓取多个文本文件,对文件进行标记,并将这些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:“猫睡了”
_inverted_index = {              'the':[0,1],              '狗':[0],              '跑':[0],              '猫':[1],              '睡了':[1]              } 其中0,1是docIDs

我收到以下错误: 'Nontype'对象没有属性键。线#95

非常感谢所有帮助。

1 个答案:

答案 0 :(得分:3)

self._inverted_index是字典时,self._inverted_index.update会就地更新并返回None (就像大多数mutator一样)。因此,代码中的灾难性错误就在于:

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

self._inverted_index设置为None。只需将其更改为

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

简单地接受就地更新(变异)并且没有错误的分配!