python之类 python 中的 IndentationError

我有这样的代码

# -*- coding: utf-8 -*- 
 
class OP(object): 
 
  def RECEIVE_MESSAGE(self): 
      print("done") 
 
 
  def NOTIFIED_INVITE_INTO_GROUP(self): 
    print("done") 

但是当我运行它的时候出现了一些错误

Traceback (most recent call last): 
File "run.py", line 2, in <module> 
  from van import ERVAN 
File "/home/server/.pub/van.py", line 4, in <module> 
  from op import OP 
File "/home/server/.pub/op.py", line 9 
  def NOTIFIED_INVITE_INTO_GROUP(self): 
                                    ^ 
IndentationError: unindent does not match any outer indentation level 

有什么解决办法吗？它只有 10 行，但让我大吃一惊