jieba分词单例模式及linux权限不够情况下tmp_dir自定义

在linux环境下，没有root权限的情况下，有时会碰到如下问题：

Building prefix dict from the default dictionary ...
Loading model from cache /tmp/jieba.cache
Dumping model to file cache /tmp/jieba.cache
Dump cache file failed.
Traceback (most recent call last):
  File "/home/work/anaconda3/envs/py27/lib/python2.7/site-packages/jieba/__init__.py", line , in initialize
    _replace_file(fpath, cache_file)
OSError: [Errno ] Operation not permitted

这是因为jieba默认情况下在/tmp下存储缓存文件，然而不是root用户，权限不够。解决办法是修改默认缓存文件的目录，把缓存文件放在用户的目录下面。 jieba文档提到了tmp_dir和cache_file可以改，所以我们查看了下源码

/home/work/anaconda3/envs/py27/lib/python2.7/site-packages/jieba/__init__.py，文件52行-66行如下：

class Tokenizer(object):
 
    def __init__(self, dictionary=DEFAULT_DICT):
        self.lock = threading.RLock()
        if dictionary == DEFAULT_DICT:
            self.dictionary = dictionary
        else:
            self.dictionary = _get_abs_path(dictionary)
        self.FREQ = {}
        self.total =
        self.user_word_tag_tab = {}
        self.initialized = False
        self.tmp_dir = None
        # self.tmp_dir = '/'
        self.cache_file = None

修改源码，在64行self.tmp_dir中可以设置自定义缓存路径。

另外一种方式是在代码中修改，以下是jieba单例模式demo

 class Singleton(object):
     """
     Jieba Utils Class
     """
     _instance = None
 
     def __new__(cls, *args, **kwargs):
         if not cls._instance:
             cls._instance = super(Singleton, cls).__new__(cls, *args, **kwargs)
         return cls._instance
 
 class JiebaUtil(Singleton):
     """
     jiebautil 工具包
     """
     _jieba_instance = None
 
     def get_instance(self):
         """
         get the global jieba instance
         """
         if self._jieba_instance:
             return self._jieba_instance
         print 'initialize...'
         obj = jieba.Tokenizer()
         obj.tmp_dir = dirpath
         obj.load_userdict(user_dict_path)
         obj.initialize()
         self._jieba_instance = obj
         return obj
 
 if __name__ == '__main__':
 
     one = JiebaUtil()
     two = JiebaUtil()
 
     print one == two
 
     tkn = one.get_instance()
     tkn2 = one.get_instance()
     print tkn == tkn2
 
     print id(one), id(two)
 
     print id(tkn), id(tkn2)

在27行中可以设置自定义的他们tmp_dir缓存路径。

参考：

http://funhacks.net/2017/01/17/singleton/

https://blog.csdn.net/sijiaqi11/article/details/78601258