Assigning the result of a function call, where the function has no returnpylint (the assignment - from - no - return)

I am Vscode quote this wrong, but can run normally, especially what the hell is this?

The attached code:

 
The class UserNameList: 

_username_list={} 

@ property 
Def users (self) : 
Try: 
With the open (' username_list. Json ', 'r') as f: 
Self. _username_list=json. The load (f) 
Return the self. _username_list 
Except the Exception as e: 
Raise e 

@ users. The setter 
Def users (self, arg) : 
Try: 
With the open (' username_list. Json ', 'w') as f: 
Self. _username_list=json. Dump (f, arg, ensure_ascii=False) 
Except the Exception as e: 
Raise e 

The self in the setter. _username_list=json. Dump (f, arg, ensure_ascii=False) error, the self below red wave,