[Python-ideas] Statement local functions and classes (aka PEP 3150 is dead, say 'Hi!' to PEP 403)

[David Townshend]

How about using lambda instead of @?  lambda on its own currently raises a
syntax error, so this might be easier to implement that @.  Also, lambda is
rather more descriptive than @ since it is already used in the context of
unnamed functions.

A question: As I understand it, the function is never actually bound to its
name, i.e. in your first example the name "report_destruction" doesn't exist
after the statement. If this is the case, then there seems little point
assigning a name at all other than for providing a description. In fact,
assigning a name implies that it is reusable and that the name means
something.

I'm not sure I like the idea of allowing defs without a name, but perhaps
its something to think about. So your first example could read

   :x = weakref.ref(obj, lambda)
   def (obj):
       print("{} is being destroyed".format(obj))

or even (reusing lambda again)

   :x = weakref.ref(obj, lambda)
   lambda (obj):
       print("{} is being destroyed".format(obj))


On Thu, Oct 13, 2011 at 6:45 AM, Carl M. Johnson <
cmjohnson.mailinglist at gmail.com> wrote:

> I really like the proposal, although I would be interested to see if anyone
> can bikeshed up keywords that might be better than : or @… :-)
>
> I do have some questions about it. Does using @ instead of the name defined
> below make the implementation easier? In other words, would this cause a
> NameError on normalize because normalize isn't defined in the local
> namespace?--
>
> :sorted_list = sorted(original, key=normalize)
> def normalize(item):
>   …
>
> Or is the @ just for brevity? I assume the point is that it's not just
> brevity, but you have to use the @ in order to make the implementation
> straightforward.
>
> -- Carl Johnson
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