When I first saw this I thought: "hmmm... this seems as redundant as adding a repeat/until loop to Python; there's no chance in hell it will ever be accepted by the community or Guido, but I actually kinda like it". It's nice to see mostly positive reactions to this idea so far.
I think it's a really ingenious solution to the the anonymous function problem - don't make it anonymous! A short, throwaway name with a very localized scope is as good as a truly anonymous function and feels more Pythonic to me. We thought we wanted a better syntax than lambda for anonymous functions but Andrey shows that perhaps it wasn't what we really need. What we need is a solution to quickly and cleanly generate bits of callable code without polluting the containing namespace, without having to think too hard about unique names and while making their temporary and local nature clear from the context. Anonymity isn't one of the requirements. I really liked Nick Coghlan's property example. The names 'get' and 'set' are too short and generic to be used without a proper scope but with this syntax they are just perfect. Here's another example: w = Widget(color=Red, onClick=onClick, onMouseOver=onMouseOver) where: . def onClick(event): do_this(event.x, event.y, foo) . def onMouseOver(event): someotherwidget.do_that() The "onClick=onClick" part seems a bit redundant, right? So how about this: w = Widget(**kw) where: . color = Red . def onClick(event): do_this(event.x, event.y, blabla) . def onMouseOver(event): someotherwidget.do_that() . x, y = 100, 200 . kw = locals() I'm not really sure myself how much I like this. It has a certain charm but also feels like abuse of the feature. Note that "w = Widget(**locals()) where:" would produce the wrong result as it will include all the values in the containing scope, not just those defined in the where block. Oren -- http://mail.python.org/mailman/listinfo/python-list
