def close(self):
		'''关闭与数据库的连接'''
		if VERBOSE:
			print 'Database connection CLOSE.'
		self.conn.close()
def _on_size_spin_button_value_changed(self, size_spin_button):
    if self._locker.is_unlocked("emit_size_spin_button_value_changed"):
      self._locker.lock("update_spin_button")