[Python-ideas] Re: Python Idea - extension of 'with'

2021-04-08 Thread Christopher Barker
My application-level > exception handling is rarely that close to the file operations, > it's usually at a much higher level. With is used for lots of other things, too. Does this same point apply to other use cases? For my part, I still find the extra indentation annoying required for with to

[Python-ideas] Re: Python Idea - extension of 'with'

2021-04-08 Thread Chris Angelico
On Fri, Apr 9, 2021 at 8:22 AM Ethan Furman wrote: > > On 4/8/21 2:40 PM, Chris Angelico wrote: > > > At least in this form, it's clear that there's a sharp distinction > > between the stuff around the outside of the 'with' block and the stuff > > inside it. > > > > The semantics, as suggested, gi

[Python-ideas] Re: Python Idea - extension of 'with'

2021-04-08 Thread Greg Ewing
On 9/04/21 2:59 am, anthony.flury via Python-ideas wrote: I was wondering whether a worthwhile extension might be to allow the `with` statement to have an `except` and `else` clauses I don't think I would find this very useful. My application-level exception handling is rarely that close to the

[Python-ideas] Re: Python Idea - extension of 'with'

2021-04-08 Thread Ethan Furman
On 4/8/21 2:40 PM, Chris Angelico wrote: At least in this form, it's clear that there's a sharp distinction between the stuff around the outside of the 'with' block and the stuff inside it. The semantics, as suggested, give 'with' blocks two distinct exception-management scopes, which mostly bu

[Python-ideas] Re: Python Idea - extension of 'with'

2021-04-08 Thread Chris Angelico
On Fri, Apr 9, 2021 at 6:41 AM Ethan Furman wrote: > > On 4/8/21 1:21 PM, Chris Angelico wrote: > > On Fri, Apr 9, 2021 at 6:16 AM Ethan Furman wrote: > >> On 4/8/21 11:25 AM, Chris Angelico wrote: > > >>> Similar question: What would be the semantics of this? > >>> > >>> with contextlib.suppress(

[Python-ideas] Adding syntax for the empty set

2021-04-08 Thread ucodery
Hello, I would like to propose adding literal syntax to allow creation of an empty set without the need to call the type constructor. I believe the best choice for such a literal, and one that has been proposed before, is `{,}`. I know this idea has surfaced a few times before, but I cannot fin

[Python-ideas] Re: Python Idea - extension of 'with'

2021-04-08 Thread Ethan Furman
On 4/8/21 1:21 PM, Chris Angelico wrote: On Fri, Apr 9, 2021 at 6:16 AM Ethan Furman wrote: On 4/8/21 11:25 AM, Chris Angelico wrote: Similar question: What would be the semantics of this? with contextlib.suppress(BaseException): a = b / c except BaseException as e: print(e) Wha

[Python-ideas] Re: Python Idea - extension of 'with'

2021-04-08 Thread Chris Angelico
On Fri, Apr 9, 2021 at 6:16 AM Ethan Furman wrote: > > On 4/8/21 11:25 AM, Chris Angelico wrote: > > > Similar question: What would be the semantics of this? > > > > with contextlib.suppress(BaseException): > > a = b / c > > except BaseException as e: > > print(e) > > > > What types of e

[Python-ideas] Re: Python Idea - extension of 'with'

2021-04-08 Thread Ethan Furman
On 4/8/21 11:25 AM, Chris Angelico wrote: Similar question: What would be the semantics of this? with contextlib.suppress(BaseException): a = b / c except BaseException as e: print(e) What types of exception could be caught and what types couldn't? Well, if every exception is deriv

[Python-ideas] Re: Python Idea - extension of 'with'

2021-04-08 Thread Chris Angelico
On Fri, Apr 9, 2021 at 1:38 AM anthony.flury via Python-ideas wrote: > ... indented twice just to accommodate the outer try block. > > Treating the 'with' as an implied `try` would reduce the march to the right - > now the key processing of the resource is now indented only one level - and > the

[Python-ideas] Re: Python Idea - extension of 'with'

2021-04-08 Thread Paul Bryan
I think I like it. Q. Safe to assume this would catch exceptions from both the call to `open` as well as the call to `open.__enter__`? Q. What about something even more verbose (descriptive) like`try with open(...) as cfg:`?  🙂 Paul On Thu, 2021-04-08 at 15:59 +0100, anthony.flury via Python-i

[Python-ideas] Re: Python Idea - extension of 'with'

2021-04-08 Thread Jonathan Goble
On Thu, Apr 8, 2021, 11:39 AM anthony.flury via Python-ideas < python-ideas@python.org> wrote: > I was wondering whether a worthwhile extension might be to allow the > `with` statement to have an `except` and `else` clauses which would have > the same > > semantics as wrapping the `with` block wi

[Python-ideas] Python Idea - extension of 'with'

2021-04-08 Thread anthony.flury via Python-ideas
We are all familiar with the `with` statement for context managers, so that the resources are correctly finalized/closed in case of an exception either in terms of the resources being allocated of the processing. It is very common though to wrap the `with block` in an outer `try` block, since