def connect(self): 
        try:
            self.connection = pymongo.Connection(self.host, self.port)
            self.db = self.connection[self.name]
        except AutoReconnect:
            raise DatabaseException("It's not possible connect to the database")
def downloadNewsPage(self, strTagName=None):
        if strTagName is None:
            #未指定 tag
            lstStrObtainedTagName = self.db.fetchallCompletedObtainedTagName()
            for strObtainedTagName in lstStrObtainedTagName:
                self.downloadNewsPageWithGivenTagName(strTagName=strObtainedTagName)
        else:
            #有指定 tag 名稱
            self.downloadNewsPageWithGivenTagName(strTagName=strTagName)