On Tue, Dec 1, 2009 at 8:42 AM, spir <denis.s...@free.fr> wrote:
> Great example, thank you.
>
> By the way, do you know the idiom:
>
> def makeInc(start):
> def inc():
> inc.n += 1
> print inc.n
> inc.n = start
> # 'start' may change now
> # ...
> return inc
>
> inc= makeInc(start=3)
> inc()
>
> I find it much nicer than a pseudo default value, for it explicitely shows
> that 'n' is, conceptually speaking, an attribute of the func (read: a closure
> upvalue). Let's take advantage of the fact python funcs are real objects!
Well, if you need an attribute maintained between calls like that I
think a generator is much nicer to write:
def inc(start):
while True:
yield start
start += 1
>>> i = inc(3)
>>> i.next()
3
>>> i.next()
4
There might be a use-case where function attributes fit better, can't
think of one right now though.
Hugo
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