Favorite non-python language trick?

[Steve Jorgensen]

On 24 Jun 2005 19:09:05 +0400, Sergei Organov <osv at javad.ru> wrote:

>Steven D'Aprano <steve at REMOVETHIScyber.com.au> writes:
>
>> On Fri, 24 Jun 2005 00:55:38 -0600, Joseph Garvin wrote:
>> 
>> > I'm curious -- what is everyone's favorite trick from a non-python 
>> > language? And -- why isn't it in Python?
>> 
>> Long ago, I used to dabble in Forth. You could say, the entire Forth
>> language was a trick :-) It was interesting to be able to define your own
>> compiler commands, loop constructs and so forth.
>> 
>> One of the things I liked in Pascal was the "with" keyword. You could
>> write something like this:
>> 
>> with colour do begin
>> red := 0; blue := 255; green := 0;
>> end;
>> 
>> instead of:
>> 
>> colour.red := 0; colour.blue := 255; colour.green := 0;
>> 
>> Okay, so maybe it is more of a feature than a trick, but I miss it and it
>> would be nice to have in Python.
>
>... that quickly becomes quite messy:

 - When abused -

>with A do begin
>  .....
>  with B do begin
>    .....
>    with C do begin
>      x := y;
>    end;
>  end;
>end;

Like many features that can be helpful when used well, and harmful when used
poorly, it's not a simple question whether it should be in any given language.
It also makes sense to consider whether other features already in the language
can fill the same need (though I don't know Python well enough to address that
yet).  Even though I like "With" in VB and use it often, I always consider its
use a warning that perhaps that code should be factored into the class
somehow.