where or filter on list

[Duncan Booth]

skip at pobox.com wrote:

> 
>     >> Another way might be to sort by absolute value:
>     >> 
>     >> intermed = [(abs(v), v) for v in foo]
>     >> intermed.sort()
>     >> intermed[0][1]
> 
>     Duncan> It is slightly simpler if you use sorted (assuming a recent
>     Duncan> enough Python):
> 
>     Duncan>     intermed = sorted(foo, key=abs)
>     Duncan>     print intermed[0]
> 
> Yeah, sorted() is new enough that my brain generally doesn't realize it's
> available.  I also never remember the key parameter to list.sort().

You're not the only one who has trouble remembering just what is in each 
version.

>  Now that you mention it:
> 
>     >>> foo = [5, 2, -1, -7, 3, -6, 2, 12]
>     >>> foo.sort(key=abs)
>     >>> foo
>     [-1, 2, 2, 3, 5, -6, -7, 12]
> 
> (assuming you don't mind reording the list - if you do, then sorted() is
> your friend).

And for Python 2.5 users only we have the exciting new option of:

>>> foo = [5, 2, -1, -7, 3, -6, 2, 12]
>>> min(foo, key=abs)
-1