On Mon, Sep 12, 2016 at 5:45 PM, Rob Cliffe <rob.cli...@btinternet.com> wrote: > > > On 12/09/2016 16:37, Guido van Rossum wrote: >> >> For the record, I still really don't like PEP 463. We should strive to >> catch fewer exceptions, not make it easier to catch them. > > Can you please clarify what you are saying in the last sentence? > The first time I read it, my brain parsed it as "People should raise fewer > exceptions, i.e. use LBYL less".
(If that means "Leap Before You Look", yes. :-) > Later it seemed more likely that you meant "The set of exceptions we catch > in a specific piece of code should not be too large; we should only catch > those exceptions that we really mean to handle". > But perhaps you mean something else altogether? > > Also I don't see the connection between the first sentence and the second. > Exception-catching expressions as per PEP 463 just give you a more concise > way of of doing something you can do with try+except. Do you mean it would > make it easier to catch exceptions because you have to type fewer > characters, and that this would be a bad thing? Yeah, that's exactly my point. PEP 463 gives you a shorter way to catch an exception, so it gives you less motivation to find a way to write your code (or define your API) that doesn't involve catching exceptions. But APIs involving exceptions are often inferior to APIs that don't require exception catching. (Yes, I am aware of __next__() raising StopIteration -- but that API design usually doesn't require you to catch it.) -- --Guido van Rossum (python.org/~guido) _______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/
