def Value(self):
        """
        Returns:
            (string) 当前cell对应的value
        """
        value = POINTER(c_ubyte)()
        vallen = c_uint64()
        lib.tera_row_reader_value(self.reader, byref(value), byref(vallen))
        return copy_string_to_user(value, long(vallen.value))