[Python-Dev] What's the status of PEP 505: None-aware operators?

[Chris Angelico]

On Tue, Dec 12, 2017 at 7:39 PM, Michel Desmoulin
<desmoulinmichel at gmail.com> wrote:
>
>
> Le 29/11/2017 à 19:02, Barry Warsaw a écrit :
>> On Nov 29, 2017, at 12:40, David Mertz <mertz at gnosis.cx> wrote:
>>
>>> I think some syntax could be possible to only "catch" some exceptions and let others propagate.  Maybe:
>>>
>>>    val = name.strip()[4:].upper() except (AttributeError, KeyError): -1
>>>
>>> I don't really like throwing a colon in an expression though.  Perhaps some other word or symbol could work instead.  How does this read:
>>>
>>>    val = name.strip()[4:].upper() except -1 in (AttributeError, KeyError)
>>
>> I don’t know whether I like any of this <wink> but I think a more natural spelling would be:
>>
>>    val = name.strip()[4:].upper() except (AttributeError, KeyError) as -1
>>
>> which could devolve into:
>>
>>    val = name.strip()[4:].upper() except KeyError as -1
>>
>> or:
>>
>>    val = name.strip()[4:].upper() except KeyError # Implicit `as None`
>>
>> I would *not* add any spelling for an explicit bare-except equivalent.  You would have to write:
>>
>>    val = name.strip()[4:].upper() except Exception as -1
>>
>> Cheers,
>> -Barry
>>
>
> I really like this one. It's way more general. I can see a use for
> IndexError as well (lists don't have the dict.get() method).
>
> Also I would prefer not to use "as" this way. In the context of an
> exception, "as" already binds the exception to a variable so it's confusing.
>
> What about:
>
>
> val = name.strip()[4:].upper() except Exception: -1

That happens to be the exact syntax recommended by PEP 463 (modulo
some distinguishing parentheses).

https://www.python.org/dev/peps/pep-0463/

ChrisA