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 153, in initialize
    _replace_file(fpath, cache_file)
OSError: [Errno 1] 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 = 0
        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