typing: property/setter and lists? [RESOLVED ERRATA]

[Paulo da Silva]

Às 07:52 de 04/11/22, dn escreveu:
> On 04/11/2022 07.50, Chris Angelico wrote:
>> On Fri, 4 Nov 2022 at 05:48, Paulo da Silva
>> <p_d_a_s_i_l_v_a_ns at nonetnoaddress.pt> wrote:
>>>
>>> Às 05:32 de 03/11/22, Paulo da Silva escreveu:
>>>> Às 03:24 de 03/11/22, Paulo da Silva escreveu:
>>>>> Hi!
>>>>>
>>>>> And a typing problem again!!!
>>>>> _______________________________________
>>>>> class C:
>>>>>       def __init__(self):
>>>>>           self.__foos=5*[0]
>>>>>
>>>>>       @property
>>>>>       def foos(self) -> list[int]:
>>>>>           return self.__foos
>>>>>
>>>>>       @foos.setter
>>>>>       def foos(self,v: int):
>>>>>           self.__foos=[v for __i in self.__foos]
>>>>>
>>>>> c=C()
>>>>> c.foos=5
>>>>> print(c.foos)
>>>>> _______________________________________
>>>>>
>>>>> mypy gives the following error:
>>>>> error: Incompatible types in assignment (expression has type "int",
>>>>> variable has type "List[int]")
>>>>>
>>>>> How do I turn around this?
>>>>>
>>>> Changing def foos(self) -> list[int]:  to
>>>>    def foos(self) -> Union[list[int]]:
>>> I meant, of course,
>>> def foos(self) -> Union[list[int],int]:
>>>
>>
>> Ohhh! I thought this was triggering a strange quirk of the checker in
>> some way...
> 
> 
> Yes, these personal styles (?quirks) are off-putting to others.
> 
> Plus "_" means (more or less) "not used anymore"
> and for most of us, a weak-identifier name such as "i" is indeed "an 
> indexer/counter/... "
Thank you for the suggestions.
BTW, I am not a python pro programmer. I use it as a tool as many other 
tools and some other (few) languages.

..
> ...and whilst I'm griping,
> "To help us to help you please copy-paste the *exact* message"
> has been followed by:
> "I'm sorry. A bad transposition of the text."
> 
> copy-paste for the win!
> (and to keep others happy to spend their voluntary time helping you - 
> more working-with-the-team thinking to consider - please)
The full original message was there. Seemed to me that that was obvious 
considering the simplicity of the subject and the illustrative toy example.
Anyway, I'm sorry.

Thank you.
Paulo