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

[Michel Desmoulin]

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