[Python-Dev] Let's just keep lambda (original) (raw)

Jiwon Seo seojiwon at gmail.com
Thu Feb 9 10:51:58 CET 2006

On 2/8/06, "Martin v. Löwis" <martin at v.loewis.de> wrote:

Jiwon Seo wrote: > Then, is there any chance anonymous function - or closure - is > supported in python 3.0 ? Or at least have a discussion about it?

That discussion appears to be closed (or, not really: everybody can discuss, but it likely won't change anything). > (IMHO, closure is very handy for function like map, sort etc. And > having to write a function for multiple statement is kind of good in > that function name explains what it does. However, I sometimes feel > that having no name at all is clearer. Also, having to define a > function when it'll be used only once seemed inappropriate sometimes.) Hmm. Can you give real-world examples (of existing code) where you needed this?

Apparently, simplest example is,

collection.visit(lambda x: print x)

which currently is not possible. Another example is,

map(lambda x: if odd(x): return 1 else: return 0, listOfNumbers)

(however, with new if/else expression, that's not so much a problem any more.)

Also, anything with exception handling code can't be without explicit function definition.

collection.visit(lambda x: try: foo(x); except SomeError: error("error message"))

Anyway, I was just curious that if anyone is interested in having more closure-like closure in python 3.0 - in any form, not necessary an extension on lambda.

-Jiwon

Regards, Martin

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