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

Guido van Rossum guido at python.org
Tue Dec 12 14:03:46 EST 2017

And I'll never approve syntax to make it easier to just ignore all exceptions without looking at them.

On Tue, Dec 12, 2017 at 12:48 AM, Chris Angelico <rosuav at gmail.com> wrote:

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

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