On Fri, Nov 27, 2020 at 01:17:07PM +1300, Greg Ewing wrote: > On 27/11/20 2:25 am, Steven D'Aprano wrote: > >Block scoping adds semantic and implementation complexity and annoyance, > >while giving very little benefit. > > Yet in *certain situations* it seems that block scoping > is what people subconsciously assume. For example, loop > variables in list comprehensions, the leaking of which > unsettled enough people that it got changed.
I was one of those people who *liked* the fact that list comp variables leaked :-) I've come around to accept that it's okay that they don't, and that conceptually comprehensions feel like a self-contained scope, more like a function than an ordinary expression. Especially since the walrus operator now allows me to leak variables out of a comprehension if I really need to. We can have too many scopes as well as too few: - a single process-wide global scope is too few; - every (sub-)expression being its own scope is too many; so we're just arguing about where the Goldilocks Zone is. My argument is that it is *function scope*, with comprehensions considered to be an honorary function for that purpose. -- Steve _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/7XAI65SZITBYJHIOTGC3ECOZPZ6ACWKM/ Code of Conduct: http://python.org/psf/codeofconduct/
