def __check_writing_path__(self, fullpath):
     if (self.file_name == ""):
         raise DatabaseError.EmptyFileNameError()
 def __check_reading_path__(self, fullpath):
     if (self.file_name == ""):
         raise DatabaseError.EmptyFileNameError()
     if (not os.path.exists(fullpath)):
         raise DatabaseError.FileNotExistError(fullpath)