[Python-Dev] Re: Shorthand for lambda
bob at redivi.com
Wed Mar 23 19:51:18 CET 2005
On Mar 23, 2005, at 1:16 PM, Ka-Ping Yee wrote:
> On Wed, 23 Mar 2005, Reinhold Birkenfeld wrote:
>> What does you implementation do for this:
>>>>> somevar = False
>>>>> filter(_ and False, numbers)
> It fails. (For the same reason that __len__ doesn't work --
> Python insists that __nonzero__ must return an int.) Though
> i must say i have no idea what you are trying to do here.
> If you filter on False, you'll always get an empty list.
Similarly, appscript provides function versions of operators named such
as AND and OR. I suppose there could be a length one as well (in
AppleScript terminology, it would be called count), or you could
technically denote it as __len__(), but that's quite ugly.
I had implemented something quite similar to this a long time ago, but
considered it "evil" and never used it for anything:
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