[Tutor] List comprehension for dicts?

[Pete]

On 2010-08-19, at 5:25 PM, Emile van Sebille wrote:

> On 8/19/2010 7:51 AM Pete said...
>> Hi,
>> 
>> I've been reading up on list comprehensions lately, all userful and powerful stuff - trying to wrap my brain around it :)
>> 
>> As the examples all seem to relate to lists, I was wondering if there is an elegant similar way to apply a function to all keys in a dictionary?
>> 
>> (without looping over it, of course)
> 
> Just fyi, as it sounds you may not understand.  List Comprehensions loop over the list.  There's no other magic going on that avoids that.
> 
> result = [ ii for ii in lst if cond ]
> 
> is just shorthand for
> 
> result = []
> for ii in lst:
>  if cond:
>    result.append(ii)
> 
> Emile

Ah, so list comprehensions are a purely syntactic construct?

I had the feeling there might be a performance benefit of some kind.

thanks for all the contributions on this topic, it's been greatly helpful to my understanding.

-Pete