python对xapian的一个简单封装类

这段python代码对xapian的部分操作进行了简单的封装，希望对大家有用。

import xapian, config
from mmseg.search import seg_txt_2_dict

class Xapian():
    """xapian search class """

    def __init__(self):
        """init xapian search class
        :returns: class

        """
        self.db = xapian.WritableDatabase(config.xapian_index_dir, xapian.DB_CREATE_OR_OPEN)
        self.enquire = xapian.Enquire(self.db)
        self.enquire.set_sort_by_value(1, True)

    def get_document(self, id):
        """获取doc

        :id: id
        :returns: Document

        """
        return self.db.get_document(id)

    def delete_document(self,id):
        """删除索引

        :id: 索引id
        """
        try:
            return self.db.delete_document(id)
        except:
            return None

    def update_index(self, id, text=None, values=None, data=None):
        """更新索引

        :id: 要替换的id
        :doc: 新的doc
        """
        try:
            doc = self.get_document(id)
        except:
            return False

        if text:
            doc.clear_terms()#清除terms
            for word, value in seg_txt_2_dict(text).iteritems():
                doc.add_term(word)

        if values:
            doc.clear_values()
            for key, value in values.iteritems():
                doc.add_value(key, value)

        if data:
            doc.set_data(data)

        try:
            self.db.replace_document(id, doc)
            return True
        except:
            return False

    def index(self, id, text, values={}, data=''):
        """index to xapian

        :id: data id
        :text: search content is utf-8
        :returns: boolean

        """
        doc = xapian.Document()
        for word, value in seg_txt_2_dict(text).iteritems():
            print word, value
            doc.add_term(word)

        #添加value用于排序，key似乎只能是数字
        for key, value in values.iteritems():
            doc.add_value(key, value)

        if data:
            doc.set_data(data)

        try:
            self.db.replace_document(id, doc)
            return True
        except:
            return False

    def search(self, keywords, offset=0, limit=10):
        """search xapian

        :keywords: 搜索的关键字
        :offset: 起始位置
        :limit: 结束位置
        :returns: matches对象

        """
        query_list = []
        for word, value in seg_txt_2_dict(keywords.encode('utf-8')).iteritems():
            query = xapian.Query(word)
            query_list.append(query)

        if len(query_list) != 1:
            query = xapian.Query(xapian.Query.OP_AND, query_list)
        else:
            query = query_list[0]

        self.enquire.set_query(query)
        matches = self.enquire.get_mset(offset, limit, 10000)
        return matches

    def flush(self):
        """flush to disk
        :returns: flush结果

        """
        return self.db.flush()

search = Xapian()