Favorite non-python language trick?

[Roel Schroeven]

Joseph Garvin wrote:
> As someone who learned C first, when I came to Python everytime I read 
> about a new feature it was like, "Whoa! I can do that?!" Slicing, dir(), 
> getattr/setattr, the % operator, all of this was very different from C.
> 
> I'm curious -- what is everyone's favorite trick from a non-python 
> language? And -- why isn't it in Python?
> 
> Here's my current candidate:
> 
> So the other day I was looking at the language Lua. In Lua, you make a 
> line a comment with two dashes:
> 
> -- hey, this is a comment.
> 
> And you can do block comments with --[[ and ---]].
> 
> This syntax lets you do a nifty trick, where you can add or subtract a 
> third dash to change whether or not code runs:
> 
> So you can change whether or not code is commented out just by adding a 
> dash. This is much nicer than in C or Python having to get rid of """ or 
> /* and */. Of course, the IDE can compensate. But it's still neat :)

Off topic, but in C or C++ it's easier to do it using

#ifdef 1
...
#endif

Then you just have to change the 1 into 0 or vice versa. It also 
prevents problems with nested comments.

Back on topic, the lack of such a construct in Python is actually one of 
the very few things that bother me in the language. There are 
work-arounds, of course; idle, for example, has a feature that prepends 
a # to every line in the selection, or removes the # again. But not all 
editors have such a feature, and even if they have it I still need to 
select the block of code every time. Not that big a deal though.

-- 
If I have been able to see further, it was only because I stood
on the shoulders of giants.  -- Isaac Newton

Roel Schroeven