Should any() and all() take a key= argument?

[Steven D'Aprano]

On Fri, 31 Mar 2006 22:35:10 -0800, Steve R. Hastings wrote:

> The list.sort() method accepts a "key=" parameter to let you specify a
> function that will change the way it sorts.  In Python 2.5, min() and
> max() now accept a "key=" parameter that changes how the functions decide
> min or max.
> 
> Should any() and all() take a key= argument?
> 
> Example:
> 
>>>> lst = [2, 4, 42]
>>>> any(lst, key=lambda x: x == 42)
> True

In my opinion, that's an abuse of the term "key".

Here's another way of doing it:

lst = [2, 4, 42]
any(map(lambda x: x==42, lst))


> I kind of like the key= option.  The need isn't as strong as with
> .sort(), min(), and max(), but consistency can be a good thing.  I'd
> personally like to see key= anywhere it makes sense.

This isn't one of those places.


-- 
Steven.