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

Chris Angelico rosuav at gmail.com
Tue Dec 12 03:48:42 EST 2017

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 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

More information about the Python-Dev mailing list