Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.python > #105034

Re: empty clause of for loops

Show all headers | View raw

On 16.03.2016 13:57, Peter Otten wrote:
>
> I'd put that the other way round: syntactical support for every pattern
> would make for a rather unwieldy language. You have to choose carefully, and
> this requirement could easily be fulfilled by a function, first in your
> personal toolbox, then in a public libary, then in the stdlib.
>
> If you don't like exceptions implement (or find) something like
>
> items = peek(items)
> if items.has_more():
>     # at least one item
>     for item in items:
>         ...
> else:
>     # empty
>
> Only if such a function is used a lot or cannot be conceived without severe
> shortcumings adding to the syntax should be considered. The (hypothetical)
> question you should answer: which current feature would you throw out to
> make room for your cool new addition?

I am glad you asked. ;-)

I would re-use the "for-else" for this. Everything I thought I could 
make use of the "-else" clause, I was disappointed I couldn't.


I find the addition to for-loop as useful as we already have a quite 
complex try-except-else-finally clause. I don't know why for-loops 
couldn't benefit from this as well.


Best,
Sven

Back to comp.lang.python | Previous | Next | Find similar | Unroll thread

Thread

Re: empty clause of for loops "Sven R. Kunze" <srkunze@mail.de> - 2016-03-16 15:29 +0100

csiph-web